The company discovered that it costs $61 to produce 3 calculators, $165 to produce 7 calculators and $385 to produce 12 calculators how much does it cost for 6 calculators

You use ax^2+bx+c=c (x)

Use (3,61), (7,165), and (12, 385) = those are your a and b (a, b) ...

a = 2

b = 6

c = 25

c (x) = 2x^2+6x+25

Since you're looking for the price of six calculators, substitute 6 in for x

c (6) = 2*36 + 6*6 + 25

Calculate ...

Answer: $169