Question

True or False? Y varies directly with x and y = -9 when x = 3. When y = 27, the value of x is 9. someone PLEASE explain...:(

Answer 1

"y varies directly with x" is y = kx. we have to find out what k is. so we substitute -9 for y and 3 for x. -9 = 3k. can you tell me what k equals?

Answer 2

ok one sec..

Answer 3

-3?

Answer 4

oh so its false?

Answer 5

yep. so now we can substitute -3 for k and 27 for y to see if x equals 9.

27 = -3x

Answer 6

does x = 9?

Answer 7

no x=3 it says so in the prob

Answer 8

no, that says when x = 3, y = -9. y and x can be any number. k is the only variable that is constant

Answer 9

ok sso its false though?

Answer 10

*so

Answer 11

why do you think it's false? are you just guessing? :/

Answer 12

or did you do the math

Answer 13

i did the math -9=3k so -9/3=3k/3 k=-3 right o9r am i totaolly off?

Answer 14

yea, k = -3, but we're trying to find out what x equals when y = 27

Answer 15

x=-9

Answer 16

yes! which is not 9. so it's false. good job :)

Answer 17

EmmaH, k=-3. So, now you substitute it in to check what x is when y=27
27=(-3)x
x=-9
Therefore, it is false.

Answer 18

yay :) =D :D =)

Answer 19

Sorry I just realised I came in a little too late

Answer 20

thanks guys...wait are you both guys right?

Answer 21

I'm a girl :D But close enough!

Answer 22

hu ....but thanks anyways

Answer 23

Anytime!

Answer 24

i'm a

Answer 25

hahahahah

Answer 26

lolo thats a way of saying it :)

Answer 27

:)