f(150) = 1500......(150,1500)
f(650) = 3900......(650,3900)
slope = (3900 - 1500) / (650 - 150) = 2400/500 = 24/5
y = mx + b
slope(m) = 24/5
(150,1500)...x = 150 and y = 1500
now sub and find b, the y int
1500 = 24/5(150) + b
1500 = 720 + b
1500 - 720 = b
780 = b
so ur equation is y = 24/5x + 780 or f(x) = 24/5x + 780 <==
or if u need it in standard form..
y = 24/5x + 780
-24/5x + y = 780....multiply by -5
24x - 5y = - 3900 <===
