math
posted by anthy .
the total cost of manufacturing 100 cameras per week is 700 $ and 120 cameras per week is 800 $ ,the the cost equation ,assuming it to be linear is

You have two points on the graph of y(x):
(100,700) and (120,800)
The slope is 100/20 = 5
(y700)/(x100) = 5
y = 5(x100) + 700
y = 5x +200