Step-by-step explanation:
x = number of t- shirts
the function for the incurring costs is
c = 5x + 45
the function for the accumulating sale is
s = 20x
the break even point is when both functions deliver the same result.
20x = 5x + 45
15x = 45
x = 3
c = s = 5×3 + 45 = 20×3 = $60
they need to sell 3 t-shirts to break even.
at that point they will have incurred $60 in costs and collected the same amount in sales.
