Expand (2 - x)^5 and identify each part of the expression.
80x^2
-40
10
32

n = 60 shirts

Step-by-step explanation:

The break-even point is the point where revenue is equal to cost.  This means we take the equation for revenue, r = 25n, and set it equal to the equation for cost, c = 10n + 900:

25n = 10n + 900

Subtract 10n from each side:

25n - 10n = 10n + 900 - 10n

15n = 900

Divide both sides by 15:

15n/15 = 900/15

n = 60