Find the constant of variation for the relationship f (x) = 30x.

A.

10

B.

30

C.

x

D.

f (x)

For a direct variation, f (x) = kx. Therefore, for f (x) = 30x, constant of variation (k) = 30.

I believe the correct answer from the choices listed above is option B. The constant for variation of the relationship f (x) = 30x would be 30. The constant of variation is the number that relates two variables that are directly proportional or inversely proportional to one another.