Answer:
A: 960d = 52000 + 680d
B: It will take 137 days to start making a profit.
Explanation:
Part A:
She begins to make a profit when the income becomes greater than the expenses. You can write an inequality or an equation. I'll write an equation that finds when the income equals the expenses. After this point, she will begin making a profit.
income = expenses
income: the combined amount all students pay
All students pay a total of $960 per day. In d days, they pay 960d.
Total income: 960d
expenses: the original fixed amount plus the daily cost
The original fixed amount is $52,000. The daily cost is $680, so in d days, she spends 680d
Total expenses: 52000 + 680d
income = expenses
The equation is:
960d = 52000 + 680d
Part B:
Subtract 580d from both sides.
380d = 52000
Divide both sides by 380.
d = 136.84
The number of days is 136.84, or just under 137 days.
It will take 137 days to start making a profit.