当a=1,b=-3时,整式3a-{-2b+[a-(4a-3b)]}=?

问题描述:

当a=1,b=-3时,整式3a-{-2b+[a-(4a-3b)]}=?

3a-{-2b+[a-(4a-3b)]}
=3a+2b-[a-(4a-3b)]
=3a+2b-a+4a-3b
=6a-b
=6×1-(-3)
=6+3
=9