已知9^m*27^m-1的值27,求m
问题描述：
已知9^m*27^m-1的值27,求m
答
9^m×27^(m - 1) = 27
3^(2m)×3^(3m - 3) = 27
3^(2m + 3m - 3) = 27
3^(5m - 3) = 27
3^(5m - 3) = 3^3
5m - 3 = 3
5m = 6
m = 6÷5
m = 1.2