2x-3y=1
(4^2x*3/8^2y)-1
=(2^2)^2x*3/(2^3)^2y-1
=3*2^4x/2^6y-1
=3*2^(4x-6y)-1
=3*[2^(2x-3y)]²-1
=3*(2^1)²-1
=11