You have a mortgage payment of $1,248.90/month. using proportions, what is the minimum you must have in realized income per month to keep your housing expense in the acceptable range?

y - 4 = (1/3)(x - 9)  or x - 3y = -3

Step-by-step explanation:

Here we're told that the slope is 1/3 and that (9, 4) is a point on the line.  Use the point-slope formula  y - k = m(x - h).  Substitute 4 for k, 9 for h and 1/3 for m:

y - 4 = (1/3)(x - 9)  (point-slope formula)

3y - 12 = x - 9  (standard form of the same equation) = >

     -12 + 9 = x - 3y, or x - 3y = -3 (standard form)