Answer:
P = 0.5Q - 20
Step-by-step explanation:
P = kQ + c
substitute Q = 60 , P = 10 into the equation
10 = 60k + c → (1)
substitute Q = 240, P = 100 into the equation
100 = 240k + c → (2)
subtract (1) from (2) term by term to eliminate c
90 = 180k ( divide both sides by 180 )
[tex]\frac{90}{180}[/tex] = [tex]\frac{1}{2}[/tex] = 0.5 = k
substitute k = 0.5 into (1) and solve for c
10 = 60(0.5) + c
10 = 30 + c ( subtract 30 from both sides )
- 20 = c
then
P = 0.5Q - 20
