因式分解及答案 因式分解练习题及答案
\u521d\u4e00\u56e0\u5f0f\u5206\u89e3\u7ec3\u4e60\u9898\u53ca\u7b54\u6848\u4f60\u53ef\u771f\u72e0 \u8981\u8fd9\u4e48\u591a\u9898\u76ee
1. 5ax+5bx+3ay+3by
\u89e3\u6cd5\uff1a=5x(a+b)+3y(a+b)
=(5x+3y)(a+b)
2. x^3-x^2+x-1
\u89e3\u6cd5\uff1a=(x^3-x^2)+(x-1)
=x^2(x-1)+ (x-1)
=(x-1)(x^2+1)
3. x2-x-y2-y
\u89e3\u6cd5\uff1a=(x2-y2)-(x+y)
=(x+y)(x-y)-(x+y)
=(x+y)(x-y-1)
bc(b+c)+ca(c-a)-ab(a+b)
=bc(c-a+a+b)+ca(c-a)-ab(a+b)
=bc(c-a)+bc(a+b)+ca(c-a)-ab(a+b)
=bc(c-a)+ca(c-a)+bc(a+b)-ab(a+b)
=(bc+ca)(c-a)+(bc-ab)(a+b)
=c(c-a)(b+a)+b(a+b)(c-a)
=(c+b)(c-a)(a+b)\uff0e
x^2+3x-40
=x^2+3x+2.25-42.25
=(x+1.5)^2-(6.5)^2
=(x+8)(x-5)\uff0e
(x^2+x+1)(x^2+x+2)-12\u65f6\uff0c\u53ef\u4ee5\u4ee4y=x^2+x,\u5219
\u539f\u5f0f=(y+1)(y+2)-12
=y^2+3y+2-12=y^2+3y-10
=(y+5)(y-2)
=(x^2+x+5)(x^2+x-2)
=(x^2+x+5)(x+2)(x-1)\uff0e
(1+y)^2-2x^2(1+y^2)+x^4(1-y)^2
\u89e3\uff1a\u539f\u5f0f=(1+y)^2+2(1+y)x^2(1+y)+x^4(1-y)^2-2(1+y)x^2(1-y)-2x^2(1+y^2)
=[(1+y)+x^2(1-y)]^2-2(1+y)x^2(1-y)-2x^2(1+y^2)
=[(1+y)+x^2(1-y)]^2-(2x)^2
=[(1+y)+x^2(1-y)+2x]\u00b7[(1+y)+x^2(1-y)-2x]
=(x^2-x^2y+2x+y+1)(x^2-x^2y-2x+y+1)
=[(x+1)^2-y(x^2-1)][(x-1)^2-y(x^2-1)]
=(x+1)(x+1-xy+y)(x-1)(x-1-xy-y)
x^5+3x^4y-5x^3y^2+4xy^4+12y^5
\u89e3\uff1a\u539f\u5f0f=(x^5+3x^4y)-(5x^3y^2+15x^2y^3)+(4xy^4+12y^5)
=x^4(x+3y)-5x^2y^2(x+3y)+4y^4(x+3y)
=(x+3y)(x^4-5x^2y^2+4y^4)
=(x+3y)(x^2-4y^2)(x^2-y^2)
=(x+3y)(x+y)(x-y)(x+2y)(x-2y)
\u5206\u89e3\u56e0\u5f0fm +5n-mn-5m
\u89e3\uff1am +5n-mn-5m= m -5m -mn+5n
= (m -5m )+(-mn+5n)
=m(m-5)-n(m-5)
=(m-5)(m-n)
\u5206\u89e3\u56e0\u5f0fbc(b+c)+ca(c-a)-ab(a+b)
\u89e3\uff1abc(b+c)+ca(c-a)-ab(a+b)=bc(c-a+a+b)+ca(c-a)-ab(a+b)
=bc(c-a)+ca(c-a)+bc(a+b)-ab(a+b)
=c(c-a)(b+a)+b(a+b)(c-a)
=(c+b)(c-a)(a+b)
1.(2a-b)²+8ab
2.y²-2y-x²+1
3.x²-xy+yz-xz
4.6x²+5x-4
5.2a²-7ab+6b²
6.(x²-2x)²+2(x²-2x)+1
7.(x²-2x)²-14(x²-2x)-15
8.x²(x-y)+(y-x)
9.169(a+b)²-121(a-b)²
10.(x-3)(x-5)+1
\u7b54\u6848\uff1a1.(2a-b)²+8ab=(2a+b)²
2.y²-2y-x²+1=(y-1)²-x²=(y-1-x)(y-1+x)
3.x²-xy+yz-xz =x(x-y)-z(x-y)=(x-z)(x-y)
4.6x²+5x-4 =(2x-1)(3x+4)
5.2a²-7ab+6b²=(2a-3b)(a-2b)
6.(x²-2x)²+2(x²-2x)+1 =(x²-2x+1)²=(x-1)^4
7.(x²-2x)²-14(x²-2x)-15 =(x²-2x-15)(x²-2x+1)=(x+3)(x-5)(x-1)²
8.x²(x-y)+(y-x) =(x²-1)(x-y)=(x+1)(x-1)(x-y)
9.169(a+b)²-121(a-b)²
=(14a+14b-11a+11b)(14a+14b+11a-11b)
=(3a+25b)(25a+3b)
10.(x-3)(x-5)+1 =(x-3)²-2(x-3)+1 =(x-3-1)²=(x-4)²
-5a^2+16a=a(16-5a)
8x^2-4x=4x(2x-1)
15p+10p^2\uff1d5p(3+2p)
\uff0d3x^2y-6xy=-3xy(x+2y)
14m^3n^2-6m^2n^3=2m^2n^2(7m-6n)
27a^2 b^3 c+18ab^2=9ab^2(3abc+2)
18xy^2 z^3+12x^2 y^2=6xy^2(3z^3+2x)
8m^2 n^2 -6m^3 n^2=2m^2 n^2(4-3m)
\u56e0\u5f0f\u5206\u89e33a3b2c\uff0d6a2b2c2\uff0b9ab2c3\uff1d3ab^2 c(a^2-2ac+3c^2)
3.\u56e0\u5f0f\u5206\u89e3xy\uff0b6\uff0d2x\uff0d3y\uff1d(x-3)(y-2)
4.\u56e0\u5f0f\u5206\u89e3x2(x\uff0dy)\uff0by2(y\uff0dx)\uff1d(x+y)(x-y)^2
5.\u56e0\u5f0f\u5206\u89e32x2\uff0d(a\uff0d2b)x\uff0dab\uff1d(2x-a)(x+b)
6.\u56e0\u5f0f\u5206\u89e3a4\uff0d9a2b2\uff1da^2(a+3b)(a-3b)
7.\u82e5\u5df2\u77e5x3\uff0b3x2\uff0d4\u542b\u6709x\uff0d1\u7684\u56e0\u5f0f\uff0c\u8bd5\u5206\u89e3x3\uff0b3x2\uff0d4\uff1d(x-1)(x+2)^2
8.\u56e0\u5f0f\u5206\u89e3ab(x2\uff0dy2)\uff0bxy(a2\uff0db2)\uff1d(ay+bx)(ax-by)
9.\u56e0\u5f0f\u5206\u89e3(x\uff0by)(a\uff0db\uff0dc)\uff0b(x\uff0dy)(b\uff0bc\uff0da)\uff1d2y(a-b-c)
10.\u56e0\u5f0f\u5206\u89e3a2\uff0da\uff0db2\uff0db\uff1d(a+b)(a-b-1)
11.\u56e0\u5f0f\u5206\u89e3(3a\uff0db)2\uff0d4(3a\uff0db)(a\uff0b3b)\uff0b4(a\uff0b3b)2\uff1d[3a-b-2(a+3b)]^2=(a-7b)^2
12.\u56e0\u5f0f\u5206\u89e3(a\uff0b3)2\uff0d6(a\uff0b3)\uff1d(a+3)(a-3)
13.\u56e0\u5f0f\u5206\u89e3(x\uff0b1)2(x\uff0b2)\uff0d(x\uff0b1)(x\uff0b2)2\uff1d-(x+1)(x+2) abc\uff0bab\uff0d4a\uff1da(bc+b-4)
(2)16x2\uff0d81\uff1d(4x+9)(4x-9)
(3)9x2\uff0d30x\uff0b25\uff1d(3x-5)^2
(4)x2\uff0d7x\uff0d30\uff1d(x-10)(x+3)
35.\u56e0\u5f0f\u5206\u89e3x2\uff0d25\uff1d(x+5)(x-5)
36.\u56e0\u5f0f\u5206\u89e3x2\uff0d20x\uff0b100\uff1d(x-10)^2
37.\u56e0\u5f0f\u5206\u89e3x2\uff0b4x\uff0b3\uff1d(x+1)(x+3)
38.\u56e0\u5f0f\u5206\u89e34x2\uff0d12x\uff0b5\uff1d(2x-1)(2x-5)
39.\u56e0\u5f0f\u5206\u89e3\u4e0b\u5217\u5404\u5f0f\uff1a (1)3ax2\uff0d6ax\uff1d3ax(x-2) (2)x(x\uff0b2)\uff0dx\uff1dx(x+1) (3)x2\uff0d4x\uff0dax\uff0b4a\uff1d(x-4)(x-a) (4)25x2\uff0d49\uff1d(5x-9)(5x+9) (5)36x2\uff0d60x\uff0b25\uff1d(6x-5)^2 (6)4x2\uff0b12x\uff0b9\uff1d(2x+3)^2 (7)x2\uff0d9x\uff0b18\uff1d(x-3)(x-6) (8)2x2\uff0d5x\uff0d3\uff1d(x-3)(2x+1) (9)12x2\uff0d50x\uff0b8\uff1d2(6x-1)(x-4)
40.\u56e0\u5f0f\u5206\u89e3(x\uff0b2)(x\uff0d3)\uff0b(x\uff0b2)(x\uff0b4)\uff1d(x+2)(2x-1)
41.\u56e0\u5f0f\u5206\u89e32ax2\uff0d3x\uff0b2ax\uff0d3\uff1d (x+1)(2ax-3)
42.\u56e0\u5f0f\u5206\u89e39x2\uff0d66x\uff0b121\uff1d(3x-11)^2
43.\u56e0\u5f0f\u5206\u89e38\uff0d2x2\uff1d2(2+x)(2-x)
44.\u56e0\u5f0f\u5206\u89e3x2\uff0dx\uff0b14 \uff1d\u6574\u6570\u5185\u65e0\u6cd5\u5206\u89e3
45.\u56e0\u5f0f\u5206\u89e39x2\uff0d30x\uff0b25\uff1d(3x-5)^2
46.\u56e0\u5f0f\u5206\u89e3\uff0d20x2\uff0b9x\uff0b20\uff1d(-4x+5)(5x+4)
47.\u56e0\u5f0f\u5206\u89e312x2\uff0d29x\uff0b15\uff1d(4x-3)(3x-5)
48.\u56e0\u5f0f\u5206\u89e336x2\uff0b39x\uff0b9\uff1d3(3x+1)(4x+3)
49.\u56e0\u5f0f\u5206\u89e321x2\uff0d31x\uff0d22\uff1d(21x+11)(x-2)
50.\u56e0\u5f0f\u5206\u89e39x4\uff0d35x2\uff0d4\uff1d(9x^2+1)(x+2)(x-2)
51.\u56e0\u5f0f\u5206\u89e3(2x\uff0b1)(x\uff0b1)\uff0b(2x\uff0b1)(x\uff0d3)\uff1d2(x-1)(2x+1)
52.\u56e0\u5f0f\u5206\u89e32ax2\uff0d3x\uff0b2ax\uff0d3\uff1d(x+1)(2ax-3)
53.\u56e0\u5f0f\u5206\u89e3x(y\uff0b2)\uff0dx\uff0dy\uff0d1\uff1d(x-1)(y+1)
54.\u56e0\u5f0f\u5206\u89e3(x2\uff0d3x)\uff0b(x\uff0d3)2\uff1d(x-3)(2x-3)
55.\u56e0\u5f0f\u5206\u89e39x2\uff0d66x\uff0b121\uff1d(3x-11)^2
56.\u56e0\u5f0f\u5206\u89e38\uff0d2x2\uff1d2(2-x)(2+x)
57.\u56e0\u5f0f\u5206\u89e3x4\uff0d1\uff1d(x-1)(x+1)(x^2+1)
58.\u56e0\u5f0f\u5206\u89e3x2\uff0b4x\uff0dxy\uff0d2y\uff0b4\uff1d(x+2)(x-y+2)
59.\u56e0\u5f0f\u5206\u89e34x2\uff0d12x\uff0b5\uff1d(2x-1)(2x-5)
60.\u56e0\u5f0f\u5206\u89e321x2\uff0d31x\uff0d22\uff1d(21x+11)(x-2)
61.\u56e0\u5f0f\u5206\u89e34x2\uff0b4xy\uff0by2\uff0d4x\uff0d2y\uff0d3\uff1d(2x+y-3)(2x+y+1)
62.\u56e0\u5f0f\u5206\u89e39x5\uff0d35x3\uff0d4x\uff1dx(9x^2+1)(x+2)(x-2)
\u4f60\u53ef\u771f\u72e0 \u8981\u8fd9\u4e48\u591a\u9898\u76ee
1. 5ax+5bx+3ay+3by
\u89e3\u6cd5\uff1a=5x(a+b)+3y(a+b)
=(5x+3y)(a+b)
2. x^3-x^2+x-1
\u89e3\u6cd5\uff1a=(x^3-x^2)+(x-1)
=x^2(x-1)+ (x-1)
=(x-1)(x^2+1)
3. x2-x-y2-y
\u89e3\u6cd5\uff1a=(x2-y2)-(x+y)
=(x+y)(x-y)-(x+y)
=(x+y)(x-y-1)
bc(b+c)+ca(c-a)-ab(a+b)
=bc(c-a+a+b)+ca(c-a)-ab(a+b)
=bc(c-a)+bc(a+b)+ca(c-a)-ab(a+b)
=bc(c-a)+ca(c-a)+bc(a+b)-ab(a+b)
=(bc+ca)(c-a)+(bc-ab)(a+b)
=c(c-a)(b+a)+b(a+b)(c-a)
=(c+b)(c-a)(a+b)\uff0e
x^2+3x-40
=x^2+3x+2.25-42.25
=(x+1.5)^2-(6.5)^2
=(x+8)(x-5)\uff0e
(x^2+x+1)(x^2+x+2)-12\u65f6\uff0c\u53ef\u4ee5\u4ee4y=x^2+x,\u5219
\u539f\u5f0f=(y+1)(y+2)-12
=y^2+3y+2-12=y^2+3y-10
=(y+5)(y-2)
=(x^2+x+5)(x^2+x-2)
=(x^2+x+5)(x+2)(x-1)\uff0e
(1+y)^2-2x^2(1+y^2)+x^4(1-y)^2
\u89e3\uff1a\u539f\u5f0f=(1+y)^2+2(1+y)x^2(1+y)+x^4(1-y)^2-2(1+y)x^2(1-y)-2x^2(1+y^2)
=[(1+y)+x^2(1-y)]^2-2(1+y)x^2(1-y)-2x^2(1+y^2)
=[(1+y)+x^2(1-y)]^2-(2x)^2
=[(1+y)+x^2(1-y)+2x]\u00b7[(1+y)+x^2(1-y)-2x]
=(x^2-x^2y+2x+y+1)(x^2-x^2y-2x+y+1)
=[(x+1)^2-y(x^2-1)][(x-1)^2-y(x^2-1)]
=(x+1)(x+1-xy+y)(x-1)(x-1-xy-y)
x^5+3x^4y-5x^3y^2+4xy^4+12y^5
\u89e3\uff1a\u539f\u5f0f=(x^5+3x^4y)-(5x^3y^2+15x^2y^3)+(4xy^4+12y^5)
=x^4(x+3y)-5x^2y^2(x+3y)+4y^4(x+3y)
=(x+3y)(x^4-5x^2y^2+4y^4)
=(x+3y)(x^2-4y^2)(x^2-y^2)
=(x+3y)(x+y)(x-y)(x+2y)(x-2y)
\u5206\u89e3\u56e0\u5f0fm +5n-mn-5m
\u89e3\uff1am +5n-mn-5m= m -5m -mn+5n
= (m -5m )+(-mn+5n)
=m(m-5)-n(m-5)
=(m-5)(m-n)
\u5206\u89e3\u56e0\u5f0fbc(b+c)+ca(c-a)-ab(a+b)
\u89e3\uff1abc(b+c)+ca(c-a)-ab(a+b)=bc(c-a+a+b)+ca(c-a)-ab(a+b)
=bc(c-a)+ca(c-a)+bc(a+b)-ab(a+b)
=c(c-a)(b+a)+b(a+b)(c-a)
=(c+b)(c-a)(a+b)
1.(2a-b)²+8ab
2.y²-2y-x²+1
3.x²-xy+yz-xz
4.6x²+5x-4
5.2a²-7ab+6b²
6.(x²-2x)²+2(x²-2x)+1
7.(x²-2x)²-14(x²-2x)-15
8.x²(x-y)+(y-x)
9.169(a+b)²-121(a-b)²
10.(x-3)(x-5)+1
\u7b54\u6848\uff1a1.(2a-b)²+8ab=(2a+b)²
2.y²-2y-x²+1=(y-1)²-x²=(y-1-x)(y-1+x)
3.x²-xy+yz-xz =x(x-y)-z(x-y)=(x-z)(x-y)
4.6x²+5x-4 =(2x-1)(3x+4)
5.2a²-7ab+6b²=(2a-3b)(a-2b)
6.(x²-2x)²+2(x²-2x)+1 =(x²-2x+1)²=(x-1)^4
7.(x²-2x)²-14(x²-2x)-15 =(x²-2x-15)(x²-2x+1)=(x+3)(x-5)(x-1)²
8.x²(x-y)+(y-x) =(x²-1)(x-y)=(x+1)(x-1)(x-y)
9.169(a+b)²-121(a-b)²
=(14a+14b-11a+11b)(14a+14b+11a-11b)
=(3a+25b)(25a+3b)
10.(x-3)(x-5)+1 =(x-3)²-2(x-3)+1 =(x-3-1)²=(x-4)²
-5a^2+16a=a(16-5a)
8x^2-4x=4x(2x-1)
15p+10p^2\uff1d5p(3+2p)
\uff0d3x^2y-6xy=-3xy(x+2y)
14m^3n^2-6m^2n^3=2m^2n^2(7m-6n)
27a^2 b^3 c+18ab^2=9ab^2(3abc+2)
18xy^2 z^3+12x^2 y^2=6xy^2(3z^3+2x)
8m^2 n^2 -6m^3 n^2=2m^2 n^2(4-3m)
\u56e0\u5f0f\u5206\u89e33a3b2c\uff0d6a2b2c2\uff0b9ab2c3\uff1d3ab^2 c(a^2-2ac+3c^2)
3.\u56e0\u5f0f\u5206\u89e3xy\uff0b6\uff0d2x\uff0d3y\uff1d(x-3)(y-2)
4.\u56e0\u5f0f\u5206\u89e3x2(x\uff0dy)\uff0by2(y\uff0dx)\uff1d(x+y)(x-y)^2
5.\u56e0\u5f0f\u5206\u89e32x2\uff0d(a\uff0d2b)x\uff0dab\uff1d(2x-a)(x+b)
6.\u56e0\u5f0f\u5206\u89e3a4\uff0d9a2b2\uff1da^2(a+3b)(a-3b)
7.\u82e5\u5df2\u77e5x3\uff0b3x2\uff0d4\u542b\u6709x\uff0d1\u7684\u56e0\u5f0f\uff0c\u8bd5\u5206\u89e3x3\uff0b3x2\uff0d4\uff1d(x-1)(x+2)^2
8.\u56e0\u5f0f\u5206\u89e3ab(x2\uff0dy2)\uff0bxy(a2\uff0db2)\uff1d(ay+bx)(ax-by)
9.\u56e0\u5f0f\u5206\u89e3(x\uff0by)(a\uff0db\uff0dc)\uff0b(x\uff0dy)(b\uff0bc\uff0da)\uff1d2y(a-b-c)
10.\u56e0\u5f0f\u5206\u89e3a2\uff0da\uff0db2\uff0db\uff1d(a+b)(a-b-1)
11.\u56e0\u5f0f\u5206\u89e3(3a\uff0db)2\uff0d4(3a\uff0db)(a\uff0b3b)\uff0b4(a\uff0b3b)2\uff1d[3a-b-2(a+3b)]^2=(a-7b)^2
12.\u56e0\u5f0f\u5206\u89e3(a\uff0b3)2\uff0d6(a\uff0b3)\uff1d(a+3)(a-3)
13.\u56e0\u5f0f\u5206\u89e3(x\uff0b1)2(x\uff0b2)\uff0d(x\uff0b1)(x\uff0b2)2\uff1d-(x+1)(x+2) abc\uff0bab\uff0d4a\uff1da(bc+b-4)
(2)16x2\uff0d81\uff1d(4x+9)(4x-9)
(3)9x2\uff0d30x\uff0b25\uff1d(3x-5)^2
(4)x2\uff0d7x\uff0d30\uff1d(x-10)(x+3)
35.\u56e0\u5f0f\u5206\u89e3x2\uff0d25\uff1d(x+5)(x-5)
36.\u56e0\u5f0f\u5206\u89e3x2\uff0d20x\uff0b100\uff1d(x-10)^2
37.\u56e0\u5f0f\u5206\u89e3x2\uff0b4x\uff0b3\uff1d(x+1)(x+3)
38.\u56e0\u5f0f\u5206\u89e34x2\uff0d12x\uff0b5\uff1d(2x-1)(2x-5)
39.\u56e0\u5f0f\u5206\u89e3\u4e0b\u5217\u5404\u5f0f\uff1a (1)3ax2\uff0d6ax\uff1d3ax(x-2) (2)x(x\uff0b2)\uff0dx\uff1dx(x+1) (3)x2\uff0d4x\uff0dax\uff0b4a\uff1d(x-4)(x-a) (4)25x2\uff0d49\uff1d(5x-9)(5x+9) (5)36x2\uff0d60x\uff0b25\uff1d(6x-5)^2 (6)4x2\uff0b12x\uff0b9\uff1d(2x+3)^2 (7)x2\uff0d9x\uff0b18\uff1d(x-3)(x-6) (8)2x2\uff0d5x\uff0d3\uff1d(x-3)(2x+1) (9)12x2\uff0d50x\uff0b8\uff1d2(6x-1)(x-4)
40.\u56e0\u5f0f\u5206\u89e3(x\uff0b2)(x\uff0d3)\uff0b(x\uff0b2)(x\uff0b4)\uff1d(x+2)(2x-1)
41.\u56e0\u5f0f\u5206\u89e32ax2\uff0d3x\uff0b2ax\uff0d3\uff1d (x+1)(2ax-3)
42.\u56e0\u5f0f\u5206\u89e39x2\uff0d66x\uff0b121\uff1d(3x-11)^2
43.\u56e0\u5f0f\u5206\u89e38\uff0d2x2\uff1d2(2+x)(2-x)
44.\u56e0\u5f0f\u5206\u89e3x2\uff0dx\uff0b14 \uff1d\u6574\u6570\u5185\u65e0\u6cd5\u5206\u89e3
45.\u56e0\u5f0f\u5206\u89e39x2\uff0d30x\uff0b25\uff1d(3x-5)^2
46.\u56e0\u5f0f\u5206\u89e3\uff0d20x2\uff0b9x\uff0b20\uff1d(-4x+5)(5x+4)
47.\u56e0\u5f0f\u5206\u89e312x2\uff0d29x\uff0b15\uff1d(4x-3)(3x-5)
48.\u56e0\u5f0f\u5206\u89e336x2\uff0b39x\uff0b9\uff1d3(3x+1)(4x+3)
49.\u56e0\u5f0f\u5206\u89e321x2\uff0d31x\uff0d22\uff1d(21x+11)(x-2)
50.\u56e0\u5f0f\u5206\u89e39x4\uff0d35x2\uff0d4\uff1d(9x^2+1)(x+2)(x-2)
51.\u56e0\u5f0f\u5206\u89e3(2x\uff0b1)(x\uff0b1)\uff0b(2x\uff0b1)(x\uff0d3)\uff1d2(x-1)(2x+1)
52.\u56e0\u5f0f\u5206\u89e32ax2\uff0d3x\uff0b2ax\uff0d3\uff1d(x+1)(2ax-3)
53.\u56e0\u5f0f\u5206\u89e3x(y\uff0b2)\uff0dx\uff0dy\uff0d1\uff1d(x-1)(y+1)
54.\u56e0\u5f0f\u5206\u89e3(x2\uff0d3x)\uff0b(x\uff0d3)2\uff1d(x-3)(2x-3)
55.\u56e0\u5f0f\u5206\u89e39x2\uff0d66x\uff0b121\uff1d(3x-11)^2
56.\u56e0\u5f0f\u5206\u89e38\uff0d2x2\uff1d2(2-x)(2+x)
57.\u56e0\u5f0f\u5206\u89e3x4\uff0d1\uff1d(x-1)(x+1)(x^2+1)
58.\u56e0\u5f0f\u5206\u89e3x2\uff0b4x\uff0dxy\uff0d2y\uff0b4\uff1d(x+2)(x-y+2)
59.\u56e0\u5f0f\u5206\u89e34x2\uff0d12x\uff0b5\uff1d(2x-1)(2x-5)
60.\u56e0\u5f0f\u5206\u89e321x2\uff0d31x\uff0d22\uff1d(21x+11)(x-2)
61.\u56e0\u5f0f\u5206\u89e34x2\uff0b4xy\uff0by2\uff0d4x\uff0d2y\uff0d3\uff1d(2x+y-3)(2x+y+1)
62.\u56e0\u5f0f\u5206\u89e39x5\uff0d35x3\uff0d4x\uff1dx(9x^2+1)(x+2)(x-2)
1 x^(n+5)+9x^(n+3)-162x^(n+1)
2 (x^2+5x+6)(x^2+5x-2)+16
其他:
3 (-2)^99+(-2)^100=2^n, 求n.
4 化简 84a^2 b^3 c^4 d^2
----------------- =______ ;
-96c^2 d^3 b^5 a
2xy-x^2-y^2+z^2
--------------- =______
2xz+x^2-y^2+z^2
a^2 a^3-1
5 计算:(-a^2+ --- -a-1)* -----
a-1 a^2+a+1
1.
x^(n+5)+9x^(n+3)-162x^(n+1)
=x^(n+1)(x^4+9x²-162)
=x^(n+1)(x²+18)(x²-9)
=x^(n+1)(x²+18)(x+3)(x-3)
2.
(x²+5x+6)(x²+5x-2)+16
=(x²+5x+2+4)(x²+5x+2-4)+16
=(x²+5x+2)²-16+16
=(x²+5x+2)²
3.
2^n=(-2)^99+(-2)^100
=2^100-2^99
=2^99*(2-1)=2^99,
故n=99。
4.
(84a²b³c^4 d²)/(-96c²d³b^5 a )
=-(7ac²)/(8b²d)
(2xy-x²-y²+z²)/(2xz+x²-y²+z²)
=[z²-(x-y)²]/[(x+z)²-y²]
=[(x-y+z)(-x+y+z)]/[(x-y+z)(x+y+z)]
=(y+z-x)/(x+y+z)
5.
[-a²+a²/(a-1)-a-1]*(a³-1)/(a²+a+1)
=a²*(a³-1)/[(a²+a+1)(a-1)]+(-a²-a-1)*(a³-1)/(a²+a+1)
=a²-(a³-1)
= -a³+a²+1
-----------------------------
X(Y-Z)^2+Y(Z-X)^2+Z(X-Y)^2-4XYZ
X^4-2AX^2+X+A^2-A
(A-B)^4+(A+B)^4+(A^2+B^2)^2
(1+Y)^2-2X^2(1+Y^2)+X^4(1-Y)^2
“问牛知马”解答:
(1).X(Y-Z)^2+Y(Z-X)^2+Z(X-Y)^2-4XYZ
因为原式是三元三次齐次轮换式
所以设原式=k(x+y+z)*[m*(x^2+y^2+z^2)+n*(xy+yz+zx)]
先看x^3的系数得:m=0 ,
所以设原式=p*(x+y+z)(xy+yz+zx)
从x^2的系数看:y+z=P*(y+z) ,所以P=1
从xyz的系数看:-10=3p ,所以p=-10/3
由于P有两个不同的值,所以原题目是错误的!
要想从xyz的系数也得出P=1 ,必须把-4xyz改为:9xyz
即 x(y-z)^2 + y(z-x)^2 + z(x-y)^2 + 9xyz = (x+y+z)(xy+yz+zx)
(2).X^4-2AX^2+X+A^2-A
原式=a^2 -(2x^2+1)a +(x^4+x) (按a的降幂排列)
=a^2 -(2x^2+1)a +(x^2+x)(x^2-x+1)
=(a-x^2-x)(a-x^2+x-1) (长十字相乘)
(3).(A-B)^4+(A+B)^4+(A^2+B^2)^2
原式=3a^4 +14a^2*b^2 + 3*b^4 (展开化简)
因为△=14^2-4*3*3= 160不是完全平方数
所以原式在有理数范围内不能分解因式
可改为:(a-b)^4 +(a+b)^4 +(a^2-b^2)^2
则原式=3a^4 +10a^2*b^2 +3b^4
=(3a^2 + b^2)(a^2 + 3b^2)
(4).(1+Y)^2-2X^2(1+Y^2)+X^4(1-Y)^2
原式=(x^4-2x^2+1)*y^2 +2(1-x^4)*y + (1-2x^2+x^4) (按y的降幂排列)
=(1-x^2)*[(1-x^2)*y^2 +2(1+x^2)y + (1-x^2)]
=(1+x)(1-x)[(y+1)^2-(y-1)^2*x^2]
=(1+x)(1-x)(x+y-xy+1)(y-x+xy+1)
一、选择题
( )1.下列多项式中何者含有2x+3的因式 (1)2x3+3 (2)4x2-9 (3)6x2-11x+3 (4)2x2+x+3
( )2.下列何者是2x2-11x-21的因式? (1)(x-6) (2)(x+7) (3)(2x-3) (4)(2x+3)
( )3.下列何者为甲×丙+乙×丙的因式 (1)甲+乙×丙 (2)甲+乙 (3)甲+丙 (4)丙+乙。
( )4.下列各式中,何者不是x2-4的因式? (1)x+2 (2)x-2 (3)x2-4 (4)x2。
( )5.a2-b2的因式不可能是下列那一个? (1)a2+b2 (2)a+b (3)a-b (4)a2-b2。
( )6.下列何者错误? (1)(-a+b)2=a2-2ab+b2 (2)(a-b)(a+b)=a2-b2 (3)(a-b)2=a2-2ab-b2 (4)(4+3)2=42+8×3+32。
( )7.下列各式中,何者是2x2-11x-21的因式? (1)2x-3 (2)x+7 (3)x-7 (4)2x+7。
( )8.下列何者为2x2+3x+1与4x2-4x-3的公因式? (1)x+1 (2)x+2 (3)2x-3 (4)2x+1。
( )9.因式分解(a+2)2-3(a+2)= (1)(a+2)(a-3) (2)(a+2)(a+3) (3)(a+2)(a+1) (4)(a+2)(a-1)。
( )10.下列何者正确? (1)a2-b2=(a-b)2 (2)a2-2ab+b2=(a+b)(a-b) (3)a2+2ab+b2=(a+b)2 (4)a2+b2=(a+b)(a-b)。
( )11.因式分解9x2-1= (1)(9x+1)(9x-1) (2)(3x-1)2 (3)(3x+1)(3x-1) (4)(9x-1)2。
( )12.若5x2-7x-6=(5x+a)(x+b),则 (1)a=-3 (2)b=-2 (3)ab=6 (4)a+b=5。
( )13.x2+mx+n=(x+a)(x+b),若m<0,n>0,则 (1)a>0,b>0 (2)a<0,b<0 (3)a>0,b<0 (4)a<0,b>0。
( )14.找出下列何者是15x2+x-2的因式? (1)5x-2 (2)15x+2 (3)3x-1 (4)3x+1。
( )15.下列何者是(x-4)(x-5)-42的因式? (1)x-2 (2)x+11 (3)x-11 (4)x+3。
( )16.若6x2-25x+4=(ax+b)(cx+d)则下列何者正确? (1)abcd=25 (2)a+b+c+d=24 (3)若a=1,则必cd=6 (4)若a=1,则必d=-1。
( )17.4a2-1等於下列何式? (1)(4a-1)2 (2)(2a-1)2 (3)(4a+1)(4a-1) (4)(2a+1)(2a-1)。
( )18.x2+y2等於 (1)(x+y)2 (2)(x+y)2+2xy (3)(x-y)2+2xy (4)(x-y)2-2xy。
( )19.你能利用2片边长xcm的正方形,9片长宽各为x,1cm的长方形和4片边长1cm的正方形,拼出长为(x+4)cm的长方形,其宽为 (1)(2x+1)cm (2)(x+3)cm (3)(2x+4)cm (4)(2x+2)cm。
( )20.下列何式是2x2+3x+1与4x2-4x-3的因式? (1)2x-1 (2)2x+1
(3)2x-3 (4)x+1。
( )21.下列那一个式子不是9x2-25的因式? (1)3x+5 (2)3x-5 (3)9x+5 (4)9x2-25。
( )22.因式分解x2-3x+2=(x+a)(a+b)则 (1)a+b=3 (2)a>0,b<0
(3)ab=-2 (4)a>0,b>0。
( )23.下列各二次式,何者有因式x-1? (1)x2+5x+6 (2)x2-5x-6 (3)x2+5x-6 (4)x2-5x+6。
( )24.(-x+y)2等於 (1)-(x-y)2 (2)(x-y)2 (3)(x+y)2 (4)(-x-y)2。
( )25.若x+y=-5,x-y=15 ,则x2-y2= (1)-5 (2)-1 (3)-15 (4)1。
( )26.x2+px+q=(x+a)(x+b),若a<0,b<0,则 (1)p>0 (2)q<0 (3)pq>0 (4)q>0。
( )27.若(x-5)2-(x-5)-12可分解为(x+a)(x+b),则a+b等於 (1)-11 (2)9 (3)11 (4)-9。
( )28.ax-cx-by+cy+bx-ay可分解为下列何式? (1)(x-y)(a-b-c)
(2)(x+y)(a+b-c) (3)(x-y)(a-b+c) (4)(x-y)(a+b-c)。
( )29.下列何者正确? (1)x2+2ax+x=x(x+2a) (2)2x2-8=x2-4=(x-2)(x+2) (3)36x2-84x+49=(7-6x)2 (4)x2-6=(x-2)(x+3)。
二、填充题
1.若2x3+3x2+mx+1为x+1的倍式,则m=
2.因式分解3a3b2c-6a2b2c2+9ab2c3=
3.因式分解xy+6-2x-3y=
4.因式分解x2(x-y)+y2(y-x)=
5.因式分解2x2-(a-2b)x-ab=
6.因式分解a4-9a2b2=
7.若已知x3+3x2-4含有x-1的因式,试分解x3+3x2-4=
8.因式分解ab(x2-y2)+xy(a2-b2)=
9.因式分解(x+y)(a-b-c)+(x-y)(b+c-a)=
10.因式分解a2-a-b2-b=
11.因式分解(3a-b)2-4(3a-b)(a+3b)+4(a+3b)2=
12.因式分解(a+3)2-6(a+3)=
13.因式分解(x+1)2(x+2)-(x+1)(x+2)2=
14.若2×4×(32+1)×(34+1)×(38+1)×(316+1)=3n-1,求n= 。
15.利用平方差公式,求标准分解式4891= 。
16.2x+1是不是4x2+5x-1的因式?答: 。
17.若6x2-7x+m是2x-3的倍式,则m=
18.x2+2x+1与x2-1的公因式为 。
19.若x+2是x2+kx-8的因式,求k= 。
20.若4x2+8x+3是2x+1的倍式请因式分解4x2+8x+3= 。
21.2x+1是4x2+8x+3的因式,请因式分解4x2+8x+3= 。
22.(1)x+2 (2)x+4 (3)x+6 (4)x-6 (5)x2+2x3+24 上列何者x2-2x-24的因式 (全对才给分)
23.因式分解下列各式:
(1)abc+ab-4a= 。
(2)16x2-81= 。
(3)9x2-30x+25= 。
(4)x2-7x-30= 。
24.若x2+ax-12=(x+b)(x-2),其中a、b均为整数,则ab= 。
25.请将适当的数填入空格中:x2-16x+ =(x- )2。
26.因式分解下列各式:
(1)xy-xz+x= ;(2)6(x+1)-y(x+1)=
(3)x2-5x-px+5p= ;(4)15x2-11x-14=
27.设7x2-19x-6=(7x+a)(bx-3),且a,b为整数,则2a+b=
28.利用乘法公式展开99982-4= 。
29.计算(1.99)2-4×1.99+4之值为 。
30.若x2+ax-12可分解为(x+6)(x+b),且a,b为整数,则a+b= 。
31.已知9x2-mx+25=(3x-n)2,且n为正整数,则m+n= 。
32.若2x3+11x2+18x+9=(x+1)(ax+3)(x+b),则a-b= 。
33.2992-3992=
34.填入适当的数使其能成为完全平方式4x2-20x+ 。
35.因式分解x2-25= 。
36.因式分解x2-20x+100= 。
37.因式分解x2+4x+3= 。
38.因式分解4x2-12x+5= 。
39.因式分解下列各式:
(1)3ax2-6ax= 。
(2)x(x+2)-x= 。
(3)x2-4x-ax+4a= 。
(4)25x2-49= 。
(5)36x2-60x+25= 。
(6)4x2+12x+9= 。
(7)x2-9x+18= 。
(8)2x2-5x-3= 。
(9)12x2-50x+8= 。
40.因式分解(x+2)(x-3)+(x+2)(x+4)= 。
41.因式分解2ax2-3x+2ax-3= 。
42.因式分解9x2-66x+121= 。
43.因式分解8-2x2= 。
44.因式分解x2-x+14 = 。
45.因式分解9x2-30x+25= 。
46.因式分解-20x2+9x+20= 。
47.因式分解12x2-29x+15= 。
48.因式分解36x2+39x+9= 。
49.因式分解21x2-31x-22= 。
50.因式分解9x4-35x2-4= 。
51.因式分解(2x+1)(x+1)+(2x+1)(x-3)= 。
52.因式分解2ax2-3x+2ax-3= 。
53.因式分解x(y+2)-x-y-1= 。
54.因式分解(x2-3x)+(x-3)2= 。
55.因式分解9x2-66x+121= 。
56.因式分解8-2x2= 。
57.因式分解x4-1= 。
58.因式分解x2+4x-xy-2y+4= 。
59.因式分解4x2-12x+5= 。
60.因式分解21x2-31x-22= 。
61.因式分解4x2+4xy+y2-4x-2y-3= 。
62.因式分解9x5-35x3-4x= 。
63.因式分解下列各式:
(1)3x2-6x= 。
(2)49x2-25= 。
(3)6x2-13x+5= 。
(4)x2+2-3x= 。
(5)12x2-23x-24= 。
(6)(x+6)(x-6)-(x-6)= 。
(7)3(x+2)(x-5)-(x+2)(x-3)= 。
(8)9x2+42x+49= 。
64.9x2-30x+k可化为完全平方式(3x+a)2,则k= a= 。
65.若x2+mx-15可分解为(x+n)(x-3),m、n皆为整数,则m= n= 。
66.求下列各式的和或差或积或商。
(1)(6512 )2-(3412 )2= 。
(2)(7913 )2+2×7913 ×23 +49 = 。
(3)1998×0.48-798×0.48-798×0.52+1998×0.52= 。
67.因式分解下列各式:
(1)(x+2)-2(x+2)2= 。
(2)36x2+39x+9= 。
(3)2x2+ax-6x-3a= 。
(4)22x2-31x-21= 。
68.利用平方差,和的平方或差的平方公式,填填看
(1)49x2-1=( +1)( -1)
(2)x2+26x+ =(x+ )2
(3)x2-20x+ =(x- )2
(4)25x2-49y2=(5x+ )(5x- )
(5) -66x+121=( -11)2
69.利用公式求下列各式的值
(1)求5992-4992= (2)求(7512 )2-(2412 )2=
(3)求392+39×22+112= (4)求172-34×5+52=
(5)若2x+5y=13 +7 ,x-4y=7 -13 求2x2-3xy-20y2=
70.因式分解3ax2-6ax= 。
71.因式分解(x+1)x-5x= 。
72.因式分解(2x+1)(x-3)-(2x+1)(x-5)=
73.因式分解xy+2x-5y-10=
74.因式分解x2y2-x2-y2-6xy+4= 。
三、计算题
1.因式分解x3+2x2+2x+1
2.因式分解a2b2-a2-b2+1
3.试用除法判别15x2+x-6是不是3x+2的倍式。
4.(1)判别3x+2是不是6x2+x-2的因式?(写出计算式)
(2)如果是,请因式分解6x2+x-2。
5.a=19912 ,b=9912 ,(1)求a2-2ab+b2之值? (2)a2-b2之值?
6.判别2x+1是否4x2+8x+3的因式?如果是,请因式分解4x2+8x+3。
7.因式分解(1)3ax2-2x+3ax-2 (2)(x2-3x)+(x-3)2+2x-6。
8.设6x2-13x+k为3x-2的倍式,求k之值。
9.判别3x是不是x2之因式?(要说明理由)
10.若-2x2+ax-12,能被2x-3整除,求 (1)a=? (2)将-2x2+ax-12因式分解。
11.(1)因式分解ab-cd+ad-bc
(2)利用(1)求1990×29-1991×71+1990×71-29×1991的值。
12.利用平方差公式求1992-992=?
13.利用乘法公式求(6712 )2-(3212 )2=?
14.因式分解下列各式:
(1)(2x+3)(x-2)+(x+1)(2x+3) (2)9x2-66x+121
15.请同学用曾经学过的各种不同因式分解的方法因式分解16x2-24x+9
(1)方法1: (2)方法2:
16.因式分解下列各式:
(1)4x2-25 (2)x2-4xy+4y2 (3)利用(1)(2)之方法求a2-b2+2bc-c2
17.因式分解
(1)8x2-18 (2)x2-(a-b)x-ab
18.因式分解下列各式
(1)9x4+35x2-4 (2)x2-y2-2yz-z2
(3)a(b2-c2)-c(a2-b2)
19.因式分解(2x+1)(x+1)+(2x+1)(x-3)
20.因式分解39x2-38x+8
21.利用因式分解求(6512 )2-(3412 )2之值
22.因式分解a(b2-c2)-c(a2-b2)
23.a、b、c是整数,若a2+b2+c2+4a-8b-14c+69=0,求a+2b-3c的值
24.因式分解7(x-1)2+4(x-1)(y+2)-20(y+2)2
25.因式分解xy2-2xy-3x-y2-2y-1
26.因式分解4x2-6ax+18a2
27.因式分解20a3bc-9a2b2c-20ab3c
28.因式分解2ax2-5x+2ax-5
29.因式分解4x3+4x2-25x-25
30.因式分解(1-xy)2-(y-x)2
31.因式分解
(1)mx2-m2-x+1 (2)a2-2ab+b2-1
32.因式分解下列各式
(1)5x2-45 (2)81x3-9x (3)x2-y2-5x-5y (4)x2-y2+2yz-z2
33.因式分解:xy2-2xy-3x-y2-2y-1
34.因式分解y2(x-y)+z2(y-x)
35.设x+1是2x2+ax-3的因式,(1)求a=? (2)求2x2+ax-3=0之二根
36.(1)因式分解x2+x+y2-y-2xy=?
(2)承(1)若x-y=99求x2+x+y2-y-2xy之值?
对不起,没答案.
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绛旓細41.鍥犲紡鍒嗚В2ax2-3x+2ax-3= 銆42.鍥犲紡鍒嗚В9x2-66x+121= 銆43.鍥犲紡鍒嗚В8-2x2= 銆44.鍥犲紡鍒嗚Вx2-x+14 = 銆45.鍥犲紡鍒嗚В9x2-30x+25= 銆46.鍥犲紡鍒嗚В-20x2+9x+20= 銆47.鍥犲紡鍒嗚В12x2-29x+15= 銆48.鍥犲紡鍒嗚В36x2+39x+9= 銆49.鍥犲紡鍒嗚В21x2-31x-22= 銆50.鍥犲紡鍒嗚В9x4-35x...
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绛旓細绛旀濡備笅锛
绛旓細=(a^2+b^2)(a^2-2ab-b^2)骞虫柟宸叕寮 (x+y)^2-8(x+y)+16 =[(x+y)-4]^2 =(x+y-4)^2 瀹屽叏骞虫柟鍏紡 9x^2+12xy+4y^2 =(3x+2y)^2 瀹屽叏骞虫柟鍏紡 3.14*21*21+6.28*10-3.14*40 =3.14*(21*21+2*10-40)鎻愬彇鍏鍥犲紡 =3.14*(441+20-40)=3.14*421 =1321.94...
绛旓細2x²-7x+3=锛2x-1)(x-3)3x²-13x+10=锛3x-10)(x-1)3x²-13x-10=((3x+2)(x-5)6x²-7x-5=(2x+1)(x-5)5x²+6xy-8y²=(5x-4y)(x+2y)6x²-11xy+3y²=(x-3y)(x-y)x鐨勫洓娆℃柟+6x²-7=(x²+7)(x²-1...
绛旓細a²-4a+4-c²=(a-2)^2-c^2=(a-2+c)(a-2-c)3x²y+28y²+7xy²+12xy==7y^2(4+x)+3xy(x+4)=(7y+3x)(x+4)y a鍥涙鏂-3a²-4=(a^2-4)(a^2+1)=(a+2)(a-2)(a^2+1)6x²-17x-10=(3x+1)(2x-10)=2(3x+1)(x-5)...
绛旓細1銆-ab(a-b)^2+a(b-a)^3 =-ab(b-a)^2+a(b-a)^3 =(b-a)^2[a(b-a)-ab]=(b-a)^2(-a^2)=-a^2(b-a)^2.2銆2m(m-7)-(7-m)(m-3)=2m(m-7)+(m-7)(m-3)=(m-7)(2m-m+3)=(m-7)(m+3).3銆169(a-b)^2-196(a+b)^2 =[13(a-b)]^2-[14(...