I have an assignment, and I'm completely stuck on this one question. Please helpp!

A parabola has equation 2y^2 = 4x + 8.

i. Express this equation in the form (y -y1)^2 = 4a(x - x1) [ those 1's were subscripts]

please help someone, it's probably the easiest question out, so its making me feel dumb right now ><

Thanksss