Question

(5a^3-2b^)-(a^3-b^2)+2(a^3-b^2),其中a=1,b=-2.

Answer 1

(5a^3-2b^2)-(a^3-b^2)+2(a^3-b^2)

=5a^3-2b^2-a^3+b^2+2a^3-2b^2

=6a^3-3b^2

=6*1^3-3*(-2)^2

=6*1-3*4

=6-12

=-6