m+2n-1=0
m+2n=1
3^3m * 27^2n
=27^m*27^2n
=27^(m+2n)
=27^1
=273^3m * 27^2n怎么变成 27^m*27^2n的。3^3m * 27^2n =(3³)^m* 27^2n = 27^m*27^2n