25^m*2*10^n=5^7*2^4
5^2m*2*(2*5)^n=5^7*2^4
5^2m*2^(n+1)*5^n=5^7*2^4
5^(2m+n)*2^(n+1)=5^7*2^4
2m+n=7 n+1=4
n=3 m=2