试一试,去括号.(1)(a+b)+(c-d)=______;(2)(a+b)-(c-d)=______;(3)a+3(-b+c-d)=________;(4)a-3(-b+c-d)=__

问题描述:

试一试,去括号.(1)(a+b)+(c-d)=______;(2)(a+b)-(c-d)=______;(3)a+3(-b+c-d)=________;(4)a-3(-b+c-d)=__
试一试,去括号.(1)(a+b)+(c-d)=_____;(2)(a+b)-(c-d)=_____;(3)a+3(-b+c-d)=_____;(4)a-3(-b+c-d)=_____.

(1)a+b+c-d (2)a+b-c+d (3)a-3b+3c-3d (4)a+3b-3c+3d