Paying $10 USD e-gold if you solve this (short) math problem

[asdfasdf]

Nvm, I gave up on it (didn't really matter anyways).

There's a store that sells marbles. The cost is measured in weight and ppl get to fill a bucket, then it's weighed but the shopkeeper subtracts whatever the bucket weighs (the weight of the bucket is what I need to know). There were like 5 or more different examples but it should/could be solved with the two that I remember:

One guy buys a 160 grams for $6.6
Another guy buys a 320 grams for $15.4

 

(160-x)y = 6.6
(320-x)y = 15.4

Set the lines equal to each other

320y-xy-15.4 = 160y-xy-6.6

therefore 160y - 8.8 = 0

8.8 / 160 = 0.055

therefore 0.055 = price per gram

6.6 / 0.055 = 120. 160-120 = 40 = weight of bucket

test: 320-40 = 280 * 0.055 = 15.4

 

[asdfasdf]

I've been away the whole evening (It's 10:30PM atm) wtihout internet access so I couldn't check this thread before now. y is the price per gram right? I don't understand this part:

320y-xy-15.4 = 160y-xy-6.6

therefore 160y - 8.8 = 0

What does setting them next to each other do? :S
And where does the 8.8 come from? I'm pretty tired atm so it could just be that but I'll look at it tomorrow before school (if I can) although it'd be nice if you or someone else could explain it further.

 

[Damien0124]

Sorry, I tried just to help you (for free xD)... but my math skills are /phail xD

 

[wtp]

320y-xy-15.4 = 160y-xy-6.6

xy and xy cancel out

320y-15.4=160y-6.6

Minus 160y
160y-15.4=6.6

Minus 6.6
160y - 8.8 = 0

And there ya go

 

Your question was answered perfectly. If you don't want to pay, you can enjoy a ban.

 

[Kabal]

Your question was answered perfectly. If you don't want to pay, you can enjoy a ban.

aahhaaaahaha railed

 

[Lucy]

Lol RSPleasant beat me to it

Yeah his steps are perfect, full working and all