## ihavemathquestions 2 years ago Determine whether y varies directly with x. If so, find the constant of variation k. 3y = –7x – 18

1. ihavemathquestions

2. ihavemathquestions

@agent0smith

3. agent0smith

For the constant of variation, we need it to look like y = kx. Let's divide both sides of 3y = –7x – 18 by 3, to get $y = -\frac{7 }{ 3 }x –\frac{ 18 }{3 }$ Try comparing $y= kx$to$y = -\frac{7 }{ 3 }x –\frac{ 18 }{3 }$

4. ihavemathquestions

5. ihavemathquestions

@agent0smith

6. agent0smith

But notice that we have$y = -\frac{7 }{ 3 }x –\frac{ 18 }{3 }$ Does it look like y=kx? or y=kx minus 18/3?

7. ihavemathquestions

no they don't so its D

8. agent0smith

For constant of variation, you only want y = kx, not y = kx plus or minus some number.

9. ihavemathquestions

so there is no constant of variation its no

10. agent0smith

Correct :) *If* it was just $y = -\frac{7 }{ 3 }x$ then it would be in the form y = kx.

11. ihavemathquestions

thanks baby xo

12. agent0smith

haha no prob :)