Answer:
The inequality required is:
and 82 tickets must be sold to pay for this year's dance.
Explanation:
Let t represents the number of tickets sold.
Given: Each ticket to the dance costs is $ 4 and the student treasure reported that the dance fund has $ 75 left over from last year.
Since, each ticket to the dance sold is $4,
therefore the total cost to the dance is 4t
Together with the $75 left carry over,
then we have; 75 + 4t
As per the given conditions :
They must make at least $400 to pay for the dance i.e it must be more than or equal to 400;
which gives you the inequality:
where t is the number of tickets sold.
Now, solve this inequality which gives you how many tickets must be sold to pay for this year's dance.
Subtraction property of equality states that you subtract the same number to both sides of an equation.
Subtract 75 to both sides of an equation;
Simplify:

Division property of equality states that you divide the same number to both sides of an equation.
divide by 4 to both sides of an equation;

Simplify:

Since, you cannot sell quarter of ticket ;
so, 81.25 rounded up to 82
therefore, 82 tickets must be sold to pay for this year's dance.