Question

计算(3m^2)^3-7m^3【m^3-m(4m^2+1)】等于 A.7m^3+9m^4 B.7m^4+48m^6 C.

Answer 1

答案B

(3m^2)^3-7m^3【m^3-m(4m^2+1)】

=27m^6-7m^3[m^3-4m^3-m]

=27m^6-7m^3[-3m^3-m]

=27m^6+21m^6+7m^4

=48m^6+7m^4

选B