Question 214078
C(x) = 20x + 10,000
R(x) = 100x
Find the profit function
Profit is  revenue - cost
or
P(x) = R(x) - C(x)
P(x) = 100x - (20x + 10,000)
P(x) = 100x - 20x - 10,000
P(x) = 80x - 10000
.

Find the breakeven point
We break even when cost = revenue
R(x) = C(x)
100x = 20x + 10,000
80x = 10000
x = 125