Answer:
![(2,8]](https://tex.z-dn.net/?f=%282%2C8%5D)
Step-by-step explanation:
Given
The attached piece wise function
Required
The domain
To do this, we simply consider the inequalities that bound the values of x.
The inequalities are:
and 
Combine the first two inequalities:
and
For the inequality to be true, we must have:
In interval notation, the inequality is:
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.
The parallelogram is 45 square meters. Multiply the base by the height. The triangle is 36 square meters. Multiply the base by the height and divide by two. Thus, the answer is 81.
