Question

Find x–y if x/y=1/7. i don't understand why you would do x+y=1? but that seems crucial in solving the problem..

Answer 1

sorry i still don't see the full solution?

Answer 2

sigh the answer key says that its -3/4

Answer 3

i appreciate your help though.

Answer 4

this is their explanation on the attached file. it makes no sense to me but maybe it will make sense to you?

Answer 5

basically you just cross multiply and simplify...

Answer 6

yeah we end up with -6x but the answer is -3/4

Answer 7

did you check my attachment?

Answer 8

Yes, I did. Cross multiplying x/y=1/7 gives y = 7x. If you substitute 7x for y in the equationx + y = 1, you then get x + 7x = 1, 8x = 1. AND x=1/8

Answer 9

THEN......

Answer 10

where did the x+y come from?

Answer 11

thats the main issue

Answer 12

well.. x+y=1..

Answer 13

okay, I see your problem. Did your teacher go over this at all with you?? You may want to talk to them about this because its kind of confusing.... What you have to do is switch the signs around because then it isn't the "stem" equation. THEN one you find the answer to that part of the equation, you can go ahead and use the x-y part of the equation

Answer 14

I can't really explain it. Its one of those things that you have to show full out....do you get what I mean?

Answer 15

uh, so do you mind drawing it?

Answer 16

@Hero can you please take a look at this question you may be able to explain better than me.

Answer 17

ok don't feel pressured..this problem sucks i know.

Answer 18

Haha, I get you....sorry, 'tis cool...

Answer 19

Umm, do you mind waiting until tomorrow for a drawing? My mom is kinda pissed Im not asleep...you know how they get when they are in their "moods"...lol. sorry about that Youngin...have you tried Googleing your question?

Answer 20

don't worry about it. get to bed before your mom kills you

Answer 21

Okay, thanks. I bookmarked this page so I can do it before I go to school tomorrow for you, Okay?

Answer 22

lol its cool. don't worry too much.

Answer 23

okay, thanks. But that drawing will be here sooner or later. PROMISE lol, i like helping people out

Answer 24

@Harkirat look at this question and see if you can give Youngin a good/better explanation than I did

Answer 25

k, now I am going to bed, lol

Answer 26

ok -just adding my 2 cents. basically when you initially asked this question you did not say that prior information supplied to you was that x + y = 1. That is crucial information

Answer 27

we all agree, 7x =y once we do cross multiplication. now rewrite the given; x + y = 1 to x + 7x =1
8x = 1
x =1/8

with that substitute back into x + y = 1
1/8 + y = 1
y = 1- 1/8
y = 8/8-1/8
y = 7/8

now you are looking for x -y

1/8 - 7/8 = -6/8 = -3/4


let me know if this is clear now.