Question

If f(x) varies directly with x, and f(x) = 45 when x = 9, find the value of f(x) when x = 3.









A.

5








B.

9








C.

15








D.

27

Answer 1

hint :
varies directly means when x increases then f(x) increases and when x decreases then f(x) decreases

Answer 2

so 27?

Answer 3

i.e. 45/9 = f(x)/3
f(x) = 3*45/9 = ?

Answer 4

it's not 27

Answer 5

15?

Answer 6

excellent!

Answer 7

@chaser71

Answer 8

This is a direct proportions problem.

45 / 9 = ? / 3

What should be the number in the place of the question mark


make sense? :D

Answer 9

oh!