Answer:
I guess that you want to find the profit:
We have two equations:
the cost equation:
C(x) = -0.1*x^2 + 100.
And the selling equation, that is a vertical stretch of the cost equation by a factor of 1.4:
S(x) = 1.4*C(x) = 1.4*( -0.1*x^2 + 100.) = -0.14*x^2 + 140
Now, whit those two equations we can find the profit equation, that is defined as the difference between the selling price, and the cost:
P(x) = S(x) - C(x) = 1.4*C(x) - C(x) = (1.4 - 1)*C(x) = 0.4*C(x).
Then the profit is 0.4 times the initial cost.
P(x) = 0.4*( -0.1*x^2 + 100.) = -0.04*x^2 + 40
