Question

If y varies directly as x, and y is 20 when x is 4, what is the constant of variation for this relation? A) 1/5 B) 4/5 C) 5 D) 16

Answer 1

y=kx
20=k*4
k=5
so option c

Answer 2

C) 5

Explanation:

The problem tell us that y is directly proportional to x, so we can represent this mathematically by:

`y=c*x`

Where:

`c=Proportionality\hspace{3}constant`

If we evaluate the data provided by the problem, then:

`20=c*4`

Solving for c, dividing both sides by 4:

`(20)/(4) =c*(4)/(4) \\5=c*1\\5=c`

Hence, the proportionality constant or the constant of variation is 5