Aha! I love these types of questions. This is where you are going to use point-slope form!
As a reminder...point slope form is
So if we have our coordinates (4, -7) -- 4 would be
and -7 would be 
-- now you need to plug them in.
But remember m = slope.
y + 7 = 3 (x - 4) -- now convert into standard form.
Standard form: y = 3x - 19
As a reminder...point slope form is
So if we have our coordinates (4, -7) -- 4 would be
But remember m = slope.
y + 7 = 3 (x - 4) -- now convert into standard form.
Standard form: y = 3x - 19