Answer:
Correct option is (C)
Step-by-step explanation:
we are given that -Tim design a pair of shorts,S, and T-shirts,t.
Tim sell Sorts for $12 and T-shirts for $8 each.
Tim can work atmost 18 hours a day so we can write 
Time taken to design a T-shirt is 30 minutes and for Shorts, it is 45 minutes.

He must design 12 itesm each day, so we can write 
Further it can be written as

Also Tim can not design more than 30 items in one day, so we can write

Hence from the above equations , its claer that

9 more than y is an expression so it would be 9+y
The most familiar case is that where you see a " + " sign between two numbers; that's an indication to add the two numbers (or terms) together.
Also, the instruction, "sum up the following," is a command to find the sum of all the numbers that follow.
Answer: 16)
(17)
(18)
(19) 3x - 18
<u>Step-by-step explanation:</u>
Inverse is when you swap the x's and y's and then solve for y
16) Given: y = x²
Swapped: x = y²

17) Given: y = 2x + 4
Swapped: x = 2y + 4
x - 4 = 2y

18) Given: y = (x + 2)²
Swapped: x = (y + 2)²
√x = y + 2

19) Given: 
Swapped: 

3(x - 6) = y
3x - 18 = y
Hi!
1. -25
2. 22
3. 0
4. -34.5
hope this helps!