若x^m=3 ,x^n=6 则x^3m-2n=__

问题描述:

若x^m=3 ,x^n=6 则x^3m-2n=__

x^3m-2n
=x^3m÷x^2n
=(x^m)³÷(x^n)²
=3³÷6²
=3/4