若m为正整数,且x^2m=3,求(3x^3m)^2-3(x^2)^2m的值.

问题描述:

若m为正整数,且x^2m=3,求(3x^3m)^2-3(x^2)^2m的值.

(3x^3m)^2-3(x^2)^2m
=9x^6m-3x^4m
=9(x^2m)^3-3(x^2m)^2
=9×3^3-3×3^2
=216