(9^m+3) ×(27^m+1) (3^4m+7)=81, 구m

(9^m+3) ×(27^m+1) (3^4m+7)=81, 구m

9^(m+3)*27^(m+1)/3^(4m+7)
=(3^2)^(m+3)*(3^3)^(m+1)/3^(4m+7)
=3^(2m+6+3m+3-4m-7)
=3^(m+2)
=81,
m+2=4, m=2