3a+5b+(2a-b)-(4a-3b)=
问题描述:
3a+5b+(2a-b)-(4a-3b)=
答
3a+5b+(2a-b)-(4a-3b)
=3a+5b+2a -b-4a+3b
=3a+2a-4a+5b-b+3b
=a+7b