若2^n=9,4^m=3,求2^2n-4m+1=_____
问题描述：
若2^n=9,4^m=3,求2^2n-4m+1=_____
答
2^n=9,
4^m=3
(2^2)^m=3
2^2m=3
2^2n-4m+1
=2^2n*2/2^4m
=(2^n)^2*2/(2^2m)^2
=9^2*2/3^2
=18