For example,
7.2, 4.3, 13.9
ANSWER
First choice
EXPLANATION
The graph of f(x) and

are symmetric about the line y=x.
This means that the graph of

is the reflection of f(x) in the line y=x.
This explains why the composition of a function and its inverse yields x, as the result.
The first choice is correct.
One way to I solve this is by listing all the ways it can be multiplied by:
72: 1*72, 2*36, 3*24, 4*18, 6*12, 8*9.
80: 1*80, 2*40, 4*20, 5*16, 8*10.
Group the factors that they have in common.
Which are 1, 2, 4, and 8.
After that, find the greatest common factor that they both share.
Answer: 8
Quotient means division....answer is C. 42/6 = 7