Question

先化简,再求值:a^3*(-b^3)^2+(-2分之1ab^2)^3,其中a=4分之1,b=4

Answer 1

a^3*(-b^3)^2+(-2分之1ab^2)^3

=a^3*b^6+(-1/2)^3*a^3*(b^2)^3

=a^3*b^6+(-1/2)^3*a^3*b^6

=a^3*b^6*[1+(-1/2)^3]

=a^3*b^6*(1-1/8)

=(1/4)^3*4^6*7/8

=4^3*7/8

=8*7

=56