[(x-2y)²+(x+2y)(x-2y)-2x(2X-y)]/2X 求化简

问题描述:

[(x-2y)²+(x+2y)(x-2y)-2x(2X-y)]/2X 求化简

[(x-2y)²+(x+2y)(x-2y)-2x(2X-y)]/2X
=[(x-2y)(x-2y+x+2y)-2x(2X-y)]/2X
=[2x(x-2y)-2x(2X-y)]/2X
=x-2y-(2x-y)
=-x-y

展开即可 原式=(-2x*2-2xy)/2X=-X-Y

[(x-2y)²+(x+2y)(x-2y)-2x(2X-y)]/2X
=[(x-2y)(x-2y+x+2y)-2x(2X-y)]/2X
=[(x-2y)(2x)-2x(2X-y)]/2X
=[(x-2y-2x+y)(2x)]/2X
=-x-y
就是乘法分配律 ab+cb=(a+c)*b