求(1+y)-2x(1+y)+x(1-y)

问题描述:

求(1+y)-2x(1+y)+x(1-y)

(1+y)-2x(1+y)+x(1-y)
=1+y-2x-2xy+x-xy
=1+y-3x-3xy
=(1+y)(1-3x)