The <em><u>correct answers</u></em> are:
The inequality is 75+4t ≥ 400, and they must sell at least 82 tickets.
Explanation:
t is the number of tickets sold. They start out with $75, so that is where our inequality begins. Each ticket is $4; this gives us the expression 4t. Together with the $75 carry over, we have 75+4t.
They must make at least $400 to pay for the dance. This means it must be more than or equal to 400; this gives us 75+4t ≥ 400.
To solve this, first subtract 75 from each side:
75+4t-75 ≥ 400-75
4t ≥ 325
Divide both sides by 4:
4t/4 ≥ 325/4
t ≥ 81.25
We cannot sell a portion of a ticket, so we round. While mathematically this number would "round down," if they only sell 81 tickets, they will not have enough money. Therefore we round up to 82.