Answer:
18
Step-by-step explanation:
7 - 5 = 2
triangle = bh/2
triangle = 2(3) / 2
triangle = 3
rect = bh
rect = 3 x 5
rect = 15
trapezoid = 15 + 3
trapezoid = 18
It's

because this choice made the most since.
X+9-3≤14
Add 3 to the other side. (do the inverse of subtraction)
x+9≤17
Subtract 9 on both sides. (the inverse of addition)
x≤8
I hope this helps!
~kaikers
Your insight that the function values differ by 5 every time is very important. So your f(x) will contain 5x as a term. You have to find a constant to add or subtract to make sure f(1)=-2.
f(x) = 5x-7 does the job.