x的平方-2x-3 因式分解()*()
(x\u7684\u5e73\u65b9-3)\u7684\u5e73\u65b9-x(x\u7684\u5e73\u65b9-3)-2x\u7684\u5e73\u65b9\u56e0\u5f0f\u5206\u89e3(x\u7684\u5e73\u65b9-3)\u7684\u5e73\u65b9-x(x\u7684\u5e73\u65b9-3)-2x
=(x^2-3-2x)(x^2-3+x)
=(x-3)(x+1)(x^2+x-3)\u671b\u91c7\u7eb3\uff0cO(\u2229_\u2229)O\u8c22\u8c22
2x\u201d - x - 3
= 2x\u201d + 2x - 3x - 3
= 2x( x + 1 ) - 3( x + 1 )
= ( x + 1 )( 2x - 3 )
\u6216\u8005
= 2x\u201d - 3x + 2x - 3
= x( 2x - 3 ) + ( 2x - 3 )
= ( x + 1 )( 2x - 3 )
这是十字相乘法
望采纳
(x-3)*(x+1)