0.64^(2m+3)<1.25^3m
(0.8^2)^(2m+3)<1.25^3m
0.8^(4m+6)<1.25^3m
[1.25^(-1)]^(4m+6)<1.25^3m
1.25^(-4m-6)<1.25^3m
-4m-6<3m
7m>-6
m>-6/7