Yes they are proportionate
Answer:
f^(-1)(x) = \frac{-1}{5} (x+4)
Step-by-step explanation:
Given is a function

To find its inverse.
We must check whether f is one to one or onto first
If -5x1-4 = -5x2-4 we get x1=x2
Hence f is one to one
Also for every f(x) we can find a x so f is onto.
So inverse exists
Let

Replace x by f inverse and y by x

Answer:
D. 240
Step-by-step explanation:
We have 20 stamps in 1 book.
We are give 12 books.
20(12) = 240
10, 0, -10
You just have to subtract by 10