Write an equation of the line with y-intercept 4 that is parallel to the line whose equation is y=3x+2

The equation through a given point (x0,y0) with a specified slope m is given by:

y=m(x-x0)+y0
Here m=3 (from y=3x+2) and (x0,y0)=(0,4) from y-intercept of 4.
Can you take it from here?