Question

Algebra plz help
suppose y varies directly with x. Write a direct variation equation that relates x and y. Then find the value of y when x=12.
y=-10 when x=2

Answer 1

a direct relationship means that as y increases, x increases as well when multiplied by a constant k.

On the contrary, an inverse relationship is when y increases and x decreases, vise versa.

Answer 2

ok I'm with you so far

Answer 3

direct variation: \( y = kx\)

indirect variation: \(y = \dfrac{k}{x}\)

Answer 4

We take our equation for direct variation, \(y=kx\) and solve for \(k\) first.\[k = \frac{y}{x}\] We can solve for the second part of the problem first when x = 2, y = -10.

Answer 5

Plug those values in for the equation for k, and tell me what you get :)

Answer 6

ok give me a second :)

Answer 7

-10=k2

Answer 8

"2k"?

Answer 9

Oh no no. solve for \[k= \frac{-10}{2}\]

Answer 10

oh ok sorry

Answer 11

No problem :)

Answer 12

k=-5

Answer 13

Good. Now that we've got our value for k, we can revert back to our original euation, \(y=kx\) and solve for \(y\) when \(x=12\) and \(k=-5\)
\[y=kx\]\[y = (-5)(12) = ~?\]

Answer 14

-60

Answer 15

Good job :)

Answer 16

thank you so much i understand how to do these now

Answer 17

Woo!

Answer 18

:D

Answer 19

hey can you help me with one more thing?

Answer 20

Hmm. I can try :)

Answer 21

You can close this question and post up a new question :)

Answer 22

That way you wont be spamming one question with multiple questions, haha

Answer 23

ok