8th grade math help needed: UPDATE

"ttyymmnn" (ttyymmnn)
09/13/2016 at 18:22 • Filed to: None

Because I haven’t into math in 30 years, maybe you brainiacs can help me out with my son’s homework. Besides, I almost failed algebra.

Office Depot makes business cards for $2.25 and a box set up fee of $4.50. FedEx Office makes business cards for $1.75 a box plus a box set up fee of $6.00. How many boxes of business cards does each company make for the price to be equal?

Update: I re-learned how to combine variable. Thanks, everybody.

DISCUSSION (24)

Textured Soy Protein > ttyymmnn
09/13/2016 at 18:00

Office Depot cost = 4.5 + 2.25x

Fedex Office cost = 6 + 1.75x

Therefore,

4.5 + 2.25x = 6 + 1.75x

I forget all that cross multiplying bullshit and what you’re supposed to do from there, so I would just plug numbers into my calculator brute force until I got the same values.

I majored in English for a reason.

Jcarr > ttyymmnn
09/13/2016 at 18:02

I used Excel, though, which probably isn’t allowed in class. Sure as hell works in the real world, though.

RamblinRover Luxury-Yacht > ttyymmnn
09/13/2016 at 18:03

Office Depot - total price is 4.50 + 2.25x, where x = number of boxes.

FedEx, 6.00 + 1.75x. Set 6.00 + 1.75x = 4.50 + 2.25x, subtract from both sides and simplify until you have a number for x. Taking 1.75x from both sides and 4.50 from both sides, you have 1.5 = 0.50x. This means they’re equal at x = three boxes, if I was paying attention to what I was doing.

EDIT: which I wasn’t, as I originally had 1.5x instead of .5x.

scoob > ttyymmnn
09/13/2016 at 18:05

yes

ttyymmnn > Textured Soy Protein
09/13/2016 at 18:05

That’s how far I got. I’ve been watching Khan Academy videos. I think I got it. I forgot how to combine variables. I forgot it was just a matter of treating them like regular numbers. So I think I’m good.

ttyymmnn > scoob
09/13/2016 at 18:06

That’s what I got! You’re a genius.

djmt1 > Textured Soy Protein
09/13/2016 at 18:06

I’m too rusty for this. I got X = -3 and something is telling me that’s wrong.

Montalvo > Textured Soy Protein
09/13/2016 at 18:09

Because there are no X^2 or other variables it is just straight forward.

.5X = 1.5

X = 2*(1.5)

X = 3

unclevanos (Ovaltine Jenkins) > scoob
09/13/2016 at 18:14

Poo can’t even do math

Highlander-Datsuns are Forever > Montalvo
09/13/2016 at 18:24

Yes this is it! X=3

X=1.5/.5 is easier for me to understand than 2*1.5 but it is the same thing.

Phyrxes once again has a wagon! > Textured Soy Protein
09/13/2016 at 18:25

Edit: didn’t see someones work that they posted before me stupid kinja.

That works fine, just combine the like terms and solve.

Dump the x terms to the left and the constants to the right.
2.25x-1.75x= 6-4.5
Combine terms
.5x = 1.5

Solving for x

x = 3

Phyrxes once again has a wagon! > ttyymmnn
09/13/2016 at 18:26

Physics and math teacher here, drop me a line of you have any issues.

Highlander-Datsuns are Forever > ttyymmnn
09/13/2016 at 18:28

High school math is going to be difficult.... oppo is here to help.

Galileo Humpkins (aka MC Clap Yo Handz) > ttyymmnn
09/13/2016 at 18:28

Nibby > ttyymmnn
09/13/2016 at 18:28

The correct answer is “Both are fucking ripoffs and just buy them online.”

vicali > ttyymmnn
09/13/2016 at 18:29

Kinja'd!!!

Wait, how did the question go again?

ttyymmnn > Phyrxes once again has a wagon!
09/13/2016 at 18:31

Thanks. My boys’ uncle is a 7th grade math teacher. We’ve had more than a few conference calls. I had to hit Khan Academy to remember how to combine variables. I could get the equation, but couldn’t get past that.

scoob > unclevanos (Ovaltine Jenkins)
09/13/2016 at 18:34

math

unclevanos (Ovaltine Jenkins) > scoob
09/13/2016 at 18:40

Find all of the first order partial derivatives for the following functions

Kinja'd!!!