已知8的n次方=5,4的m次方=7求2的4m+6n次方的值?

^ 表示乘方
8^n=5
(2³)^n=5
2^3n=5
4^m=7
(2²)^m=7
2^2m=7
2^(4m+6n)
=2^4m×2^6n
=(2^2m)²×(2^3n)²
=7²×5²
=49×25
=1225