Question

已知4^m=a,8^n=b,则2^4m-6n=?

Answer 1

4^m=2^(2m)=a;……①

8^n=2^(3n)=b;……②

2^(4m-6n)=2^2(2m-3n)……③；

①/②,得2^(2m-3n)=a/b.……④

④代入③,既得2^(4m-6n)=a^2/b^2