若3^x=6,9^y=2,求3^2x-4y+2

若3^x=6,9^y=2,求3^2x-4y+2
若3^x=6,9^y=2,求3^2x-4y+2

若3^x=6,9^y=2,求3^2x-4y+2
3^2x=(3^x)^2=6^2=36
3^-4y=1/3^4y=1/9^2y=1/(9^y)^2=1/4
3^2x-4y+2
=36x1/4x9
=81

3^(2x-4y+2)
=(3^x)^2*(3^y)^(-4)*9
=(3^x)^2*(9^y)^(-2)*9
=36*(1/4)*9
=81