(2x-3y+7)+(6x-5y-2)=?
问题描述:
(2x-3y+7)+(6x-5y-2)=?
答
(2x-3y+7)+(6x-5y-2)
=2x-3y+7+6x-5y-2
=(2x+6x)+(-3y-5y)+(7-2)
=8x+(-8y)+5
=8x-8y+5