the total cost c of a firm is partly constant and partly varies as the square of the quantity x of goods produced if 20 units of goods cost#30,000 and 45 units cost #60,000. find the cost of producing 120 units

Answer 1

Help me solve the question

Answer 2

c = a + b x^2

30,000 = a + b (400)
60,000 = a + b (2025)
------------------------------- subtract
-30,000 = - 1625 b
b = 18.4615
30,000 = a + 18.4615 (400)
a = 30,000 - 7,384.62 = 22,615.38
so
c = 22,615.38 + 18.4615 (120)^2
= 288,461.