Question

整式的乘法：先化简,再求值a(a^2-3a+1)-a^2(a-2),其中a=-2

Answer 1

a(a^2-3a+1)-a^2(a-2)

=(a^3-3a^2+a)-a^3+2a^2

=-a^2+a

将a=-2代入上式得-6