Bread Supplies

There is only one company producing bread in the economy. Its offer of bread
zero when the price of bread is equal to $ 1. When the price is equal to $ 4 provides
12 loaves of bread. Assuming that the supply of bread is now a linear function
(Prices as ins = a + bP) give its equation. (Hint: you will end up with two
equations with two unknowns are the parameters a and b, the supply
function)

0 = a + b
12 = a +4 b
a, b =-, b = 12 / 3 = 4
The supply function is S = -4 4 P