2b+3b-3a-5b+3,其中a=-1.b=2,先化简,再求值

问题描述:

2b+3b-3a-5b+3,其中a=-1.b=2,先化简,再求值

=[2+3+(-5)]b+3a+3
=3a+3
当a=-1 b=2时原式:3a+3
=3*-1+3
=0