## Sarah_Miller720 Group Title For the data in the table, does y vary directly with x? If it does, write an equation for the direct variation. x- 3 6 8 y- 6 18 24 I dont get how to solve this one year ago one year ago

1. JayDS

wow, that's weird..

2. Sarah_Miller720

these are my choices yes; y = 2x yes; y = 3x yes; y = 4x no; y does not vary directly with x

3. JayDS

oh k, I know the answer then. Which one do u think it is?

4. JayDS

think of the same concept we applied to previous similar questions.

5. Sarah_Miller720

yes; y= 3x?

6. JayDS

nope.

7. JayDS

use the point (3,6) substitute that into y=3x 6=3(3) 6=9 not correct.

8. Sarah_Miller720

yes; y = 2x

9. JayDS

nope.

10. JayDS

u have to try them for all points!!!

11. Sarah_Miller720

im confused lol

12. Sarah_Miller720

This is what i did with how you explained it above ^^ 6=3(3) this equals 9 18= 6(6) this equals 36 24= 8(8) this equals 64

13. JayDS

I'll give u another minute before explaining it.

14. JayDS

wait, u are confusing me.

15. JayDS

lol.

16. Sarah_Miller720

im confused too

17. JayDS

ok, let me explain from the very start. (3,6) , (6,18) , (8,24) These are all the points/values given. we are also given y=2x, y=3x, y=4x or it doesn't vary. **Important: The rule must work for all points. lets test all three points for y=2x (3,6) (6,18) (8,24) y=2x y=2x y=2x 6=2(3) 18=2(6) 24=2(8) 6=6 18=12 24=16 y=2x is not the answer because only (3,6) works. lets try y=3x (3,6) (6,18) (8,24) y=3x y=3x y=3x 6=3(3) 18=3(6) 24=3(8) 6=9 18=18 24=24 y=3x is not the answer because only (6,18) and (8,24) work. same thing, u can try for y=4x it will not work. Therefore our answer is......?

18. Sarah_Miller720

no; y does not vary directly with x

19. JayDS

yes u are right.

20. Sarah_Miller720

thanks so much

21. JayDS

no problem.