x-intercept = (5a,0) y-intercept = (0,3a), for some nonzero number, a.
Slope of line = (3a-0)/(0-5a) = (3a)/(-5a) = -3/5
Equation of line: y-3 = (-3/5)(x-(-4))
y-3 = (-3/5)x - (12/5)
5y-15 = -3x-12
3x+5y = 3