已知:2^m=3.2^n=5,求2^3m+2n+2的值

＝675,过程看下面：
2的3m 2n次方
=2^3m×2^2n
=(2^m)^3×(2^n)^2
=27×25
=675

因为　2^m=3, 2^n=5
所以　2^(3m+2n+2)=(2^3m)*(2^2n)*(2^2)
=[(2^m)^3]*[(2^n)^2]*4
=(3^3)*(5)^2*4
=27*25*4
=2700.

2*[3m+2n+2]=[2^3m][2^2n][2^2]
=4[(2^m)^3][(2^n)^2]
=4(27)(25)
=2700