Super Easy Math Problem! (though, I can't solve it)

[I am r4ymond]

The problem is;

"If y varies directly as x and y = 14 when x = 8, find x and y = 21."

I can solve this problem, but it's just that I'm having a LOT of debate with my friends upon checking this answer. So what I'm trying to say is, is it 147/4 or 16/3?

This is a problem from my math wksts for homework (in which the math wksts will be worth a quiz grade, so I have to take advantage of this opportunity to raise my grade).

Thanks

 

[KingdomBlade]

y=kx
14=k8
divide both sides by 8, turns into 7/4

21=7/4x
divide all by 7/4
comes up as 144/7
equal to 12.

The poster above me is right.

 

[I am r4ymond]

This is rather confusing, for the formula that I use to solve this problem is xy=k then divide k by 21. I appreciate the answers .

I'll wait for more answers to this question until tomorrow morning.

 

[KingdomBlade]

There are only 3 formulas for direct variation: y=kx, y/x=k, and y/k=x, I'm pretty sure of that. We studied this formula repeatedly, believe me.

 

[KingdomBlade]

Just in case you need more clarification.

http://www.cliffsnotes.com/study_gu...ion.topicArticleId-38949,articleId-38907.html

 

[CrimzonEyed]

Meh i use google for my math problems

http://www.blurtit.com/q4758482.html

 

[I am r4ymond]

Went through the answers today and it was indeed 12. Luckily I switched before I went over it.

Thanks for the help