Find the Equation of the tangent to the curve of e^2y + xy= 4x + 1,

What I've done so far,

e^2y + xy= 4x + 1

e^2y + xy - 4x - 1 = 0

dy/dx = 2ye^2y + 1 - 4 = 0

dy/dx = 2ye^2y - 3 = 0

I'm not sure if I've done it right because there is no x value, does this mean I sub y=0 into dy/dx instead.

Any help would be appreciated.