Question

The variable y is directly proportional to the variable x. If y = 9 when x = 5, what is the value of y when x = 20?

A) 20
B) 27
C) 32
D) 36

Answer 1

Rise over run is y over x. 9/5 is 1.8 you have x=20 i plugged in all numbers and when i plugged in 36 i got 1.8 so im sure the answer is D)36

Answer 2

The answer of the question is D) 36

Explanation:

It is stated that y is directly proportional to the variable x. Therefore, the function equation can be written as below:

`f(x)=9*x/5`

When x=5, function gives y=9. When x = 20 function is going to be as following:

`f(20)=9*20/5=36`

Correct answer is D) 36