y = mx + b is slope-intercept form.
"m" is the slope and "b" is the y-intercept.
The slope, 5/4, is in place for "m".
All you will need to do is graph the problem, so either graph a point starting at (−8, −7) that uses a rise of 5 and run of 4, or go to desmos graphing (the best graphing website in my opinion).
I will attach an image of the graph, where we see the y-intercept is (0, 3).
This means our final answer is y = 5/4x + 3.