You can read off the changes in x and y directly from the given graph. The change in y is positive and is 4-(-3), or 7, and the change in x is positive and is 4-(-4), or 8. Thus, the slope is m = 7/8.
In point-slope form:
y-3 = (7/8)(x-[-4]), or y-3 = (7/8)(x+4) (answer in point-slope form)