因式分解 (x2-2x-x)(x2-2x+4)+9
问题描述:
因式分解 (x2-2x-x)(x2-2x+4)+9
答
(x2-2x-x)(x2-2x+4)+9
(x^2-2x-x)=x(x-3) x应是个数对吗
答
因式分解 (x2-2x-2)(x2-2x+4)+9
设 x^2 - 2x = y
原式= (y-2)(y+4)+9
= y^2 + 2y - 8 + 9
= y^2 + 2y + 1
= (y+1)^2
= (x^2 - 2x + 1)^2
= (x-1)^4