The equation of a line, given the slope and a point on the line is usually written as:
y - y0 = m (x - x0)
where (x0, y0) is the point you are given and m is the slope.
It looks as though you are given a point (-3, 4) which you can put in place of x0 and y0, but m isn't defined, so you can just leave it as the letter m.
Stephen La Rocque.>