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

@iGreen

Answer 2

f(x) = 45
x = 9

Plug them in:

45 = k(9)

45 = 9k

Divide 9 to both sides, what's 45 / 9?

Answer 3

5

Answer 4

And your using "K". Does it matter which one you use? Because there is no "K" in the equation

Answer 5

5 is right

Answer 6

Yes, so the constant is '5'.

No, it doesn't..it just represents the constant..that's how they use it.

Answer 7

Now let's plug in k = 5 and x = 3 and solve for f(x).

f(x) = kx

f(x) = (5)(3)

Multiply 5 * 3

Answer 8

Ok. I have a few more. Help me with those also?

Answer 9

no wait the method which teacher was t o45/9 = 5
5 * 3 = 15
answer is 15

Answer 10

no no wait I messed up it was for some other subject not fo this one 5 is right

Answer 11

:?

Answer 12

So the answer is 15 @iGreen

Answer 13

Yes, it is.

Answer 14

wht is am right

Answer 15

@iGreen

Answer 16

Ok. I have a cpiuple more. Help me with those?

Answer 17

couple*

Answer 18

guys some one give me medal

Answer 19

pls

Answer 20

I already gave one to @iGreen Sorry

Answer 21

redo it

Answer 22

@DelTa-_-LeGEnD