At a price of $9 per box of oranges, the supply is 320,000 boxes and at a price of $8.50 per box, the supply is 270,000 boxes. Find the supply equation of the form p = mq + c, where p is the price in dollars and q is the corresponding supply in thousands of boxes.

Answer 1

p = m q + c
9.0 = 320 m + c
8.5 = 270 m + c
--------------------- subtract
0.5 = 50 m
m = 5/500 = 0.01
then
9 = 320 * 0.01 + c
9 = 3.2 + c
c = 5.8
so
p = 0.01 q + 5.8