Question

If f(x) varies directly with x, and f(x) = 56 when x = 8, find the value of f(x) when x = 2

4
7
8
14

Answer 1

@Nnesha would it be possible for you to help me with one more?

Answer 2

y = k*x

56 = k * 8

What is the value of k?

Answer 3

k = 56/8, But what happens to the 2 that is listed in the equation?

Answer 4

You can read more about direct variation here, if interested:

http://www.regentsprep.org/regents/math/algebra/AO4/Ldirect.htm

Answer 5

We have to get the equation first.
After that, we deal with the 2.

Answer 6

ok

Answer 7

so 56/8 needs to be simplyfied

Answer 8

What is 56 divided by 8. We need that for the variation constant.

Answer 9

to 7?

Answer 10

so K=7

Answer 11

So, the equation is this: y = 7*x

Answer 12

If x = 2, then use the equation to get y. Post what you get.

Answer 13

y = 14

Answer 14

Then what do i do next?

Answer 15

That is it. That is the value of f(x) when x = 2 --> 14

Answer 16

ohh i see. Thank you!

Answer 17

You are welcome.

Answer 18

I need help with one more, should i open a new question?

Answer 19

Yes.

Answer 20

ok, thanks

Answer 21

You are welcome.