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