（x-2）（x-1）=42因式分解怎么算？ x(x-1)=42
(x-2)(x-1)=42\u56e0\u5f0f\u5206\u89e3\u600e\u4e48\u5199\uff1f(x-2)(x-1)=42
x²-3x+2=42
x²-3x-40=0
\uff08x+5\uff09\uff08x-8\uff09=0
^2\u4e3a\u5e73\u65b9
1.\u5316\u4f5c\u4e00\u822c\u5f0fx^2-x-42=0
\u56e0\u5f0f\u5206\u89e3(x-7)(x+6)=0
x1=7,x2=-6
2.\u5316\u4f5c\u4e00\u822c\u5f0fx^2-x-42=0
\u516c\u5f0f\u6cd5\uff0ca=1,b=-1,c=-42\uff08\u7cfb\u6570\uff09
\u5f97x1=7,x2=-6
\u8fd9\u4e2a\u516c\u5f0f\u6cd5\uff0c\u4f60\u53ef\u4ee5\u4e0a\u7f51\u67e5\u8be2\uff0c\u9002\u7528\u4e8e\u4efb\u4f55\u65b9\u7a0b\uff0c\u4f46\u9700\u8981\u8ba1\u7b97\u3002
方法如下，
请作参考：
解答:
(x-2)(x-1)=42
x^2-3x+2=42
x^2-3x-40=0
(x+5)(x-8)=0
x1=-5，x2=8。
(x-2)(x-1) = 42
x^2 - 3x - 40 = 0
(x-8)(x+5) = 0
x1 = 8 , x2 = -5
(x-3/2)^2-1/4-42=0,
(x-3/2)-169/4=0,
(x-3/2-13/2)(x-3/2+13/2)=0,
(x-8)(x+5)=0,
解2 (x-1)^2-(x-1)-42=0,
(x-1-7)(x-1+6)=0,
(x-8)(x+5)=0,
可以吗？
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