Hi, could someone please explain how I integrate this?

$\displaystyle \int \int e^(-g(3x-4y)^4)dxdy$

where g is a positive constant

I have a Jacobian of -3, from

x = 2u + v; y =u - v

and the region is described by x is less than or equal to 0 and y is greater than or equal to 0