2^x=8^(y+1)=2^(3y+3)
x=3y+3
9^y=3^(x-9)
3^(2y)=3^(x-9)
2y=x-9
2y=3y+3-9
y=6
x=21
(1/3)x+(1/2)y
=7+3
=10