Message from Warren H in MacGuyver - Skills & Academics #homework-help


2018-01-29 02:55:24 UTC  

6 is 2\*3, and 45 = 15\*3

2018-01-29 02:55:49 UTC  

so u = (2\*3)/(15\*3)

2018-01-29 02:56:06 UTC  

the 3 on top and bottom cross out

2018-01-29 02:56:11 UTC  

so u = 2/15

2018-01-29 02:57:08 UTC  

@Warren H oh you want it the way they did it in the picture? it is similar:

2018-01-29 02:57:17 UTC  

starting from 9u = 6/5

2018-01-29 02:57:29 UTC  

Your way seems easier. There's was confusing as heck

2018-01-29 02:57:54 UTC  

How did you know 15 x 3? Instead of 9x5?

2018-01-29 02:58:03 UTC  

I'm bad with fractions lol

2018-01-29 02:58:32 UTC  

I'll do it closer to the way they did it:
starting from 9u = 6/5
divide both sides by 9, so u = (6/5) * (1/9)

2018-01-29 02:58:42 UTC  

so u = 6/(5*9)

2018-01-29 02:58:59 UTC  

now 6 is 2\*3 and 9 is 3\*3

2018-01-29 02:59:12 UTC  

so u = (2\*3)/(5\*3\*3)

2018-01-29 02:59:29 UTC  

cross out a 3 on top and bottom

2018-01-29 02:59:39 UTC  

Ohh okay.

2018-01-29 02:59:40 UTC  

so u = 2/(5*3)

2018-01-29 02:59:44 UTC  

so u = 2/15

2018-01-29 02:59:52 UTC  

yep

2018-01-29 03:00:58 UTC  

So I do that every time? Divide both sides by whatever the number is?

2018-01-29 03:01:46 UTC  

Yep that will always work

2018-01-29 03:03:49 UTC  

Awesome thanks. One more, this one is a negative number. I'm guessing it works the same?

2018-01-29 03:03:56 UTC  

-4w = 6/7

2018-01-29 03:04:42 UTC  

So divide both sides by -4 and I get 6/7 * 1/4? Or -1/4

2018-01-29 03:06:23 UTC  

Yep:
divide both sides by -4, so w = 6/(7* -4)
6 is 2\*3 and -4 is 2\*-2
so w = (2\*3) / (7\*2\*-2)
then cross out the two on top and bottom
so w = 3/(7*-2)
so w = 3/(-14) or equivalently w = -3/14

2018-01-29 03:06:48 UTC  

@Warren H the second one

2018-01-29 03:07:16 UTC  

the negative sign stays with the number it is attached to

2018-01-29 03:10:14 UTC  

Okay. So I got 3/7 the first time. But it's actually negative 3/14ths? Or -3 over 14?

2018-01-29 03:11:53 UTC  

Yep. If you're asking if there is a difference between " negative 3/14ths vs -3 over 14" the answer is no, they have the same value

2018-01-29 03:12:39 UTC  

Uh. Divide both sides by 9

2018-01-29 03:12:48 UTC  

Oh geez

2018-01-29 03:12:55 UTC  

I didn't see all this

2018-01-29 03:13:16 UTC  

@Warren H One thing you might notice at the beginning: think about the equation -4w = 6/7

2018-01-29 03:13:39 UTC  

one things you might notice is that the left side is -4 * w, and the left side is a positive number (specifically 6/7)

2018-01-29 03:13:55 UTC  

that means w times a negative number is something positive

2018-01-29 03:14:41 UTC  

so whatever w is, w must be some negative number, since -4 times a positive number would be negative.

2018-01-29 03:15:34 UTC  

@Warren H This ^ might help as a kind of double check on your work, thinking what sign the final answer should have

2018-01-29 03:16:18 UTC  

Okay yeah that makes sense.

2018-01-29 03:16:32 UTC  

Ive been working a lot with linear equations

2018-01-29 03:18:57 UTC  

@Warren H Yeah they are an important building block for a lot of things but there can be a lot to keep track of when getting used to them. Any thoughts in particular about linear equations? Let us know if you have any questions in the future!

2018-01-29 03:22:31 UTC  

Haha I don't like them lol. The worst part of math for me is fractions, and finding missing numbers like x lol

2018-01-29 03:24:41 UTC  

@Warren H haha yeah if you remember up there ^^^ the first way I wanted to solve for u... first thing I did was cross-multiplied the denominators because I don't like using fractions either if I don't have to.
Are you doing this for a math major?