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Post by
mudfish
There's only 20 posts left untill I get 5k>.>
Post by
165617
This post was from a user who has deleted their account.
Post by
mudfish
There's 14 posts left now.
Post by
150529
This post was from a user who has deleted their account.
Post by
Toldry
ALGEBRA HALP
So while I was in the Summer Vacation I forgot everything I've learned.
And I got homewurk.
Refresh my memory on now to solve this;
6 5
_ + _ < 4
x x+3
Post by
Toldry
I just came back from walking my dog and I noticed something weird....
WHY IS THE MOON ORANGE?
Edit: Google helped me find a image of how it looks like:
http://muslimmatters.org/wp-content/uploads/2008/08/red-crescent-moon.jpg
Post by
340646
This post was from a user who has deleted their account.
Post by
Hyperspacerebel
ALGEBRA HALP
So while I was in the Summer Vacation I forgot everything I've learned.
And I got homewurk.
Refresh my memory on now to solve this;
6 5
_ + _ < 4
x x+3
Multiply both sides by x * (x +3)
6x + 18 +5x < 4x^2 + 12x
4x^2 +x - 18 > 0
4x^2 - 8x + 9x - 18 > 0
4x(x-2) + 9(x - 2) > 0
(4x + 9)(x - 2) > 0
4x + 9 > 0 and x - 2 > 0 OR 4x + 9 < 0 and x - 2 < 0
x > -9/4 and x > 2 OR x < -9/4 and x < 2
Xx> 2 OR x < -9/4
I probably screwed up I'm so rusty...but the theory's correct I'm sure.
Post by
Patty
...I think you're right, Hyper. :|
I almost forgot all my GCSE maths work hehe ;)
Post by
Toldry
You can not multiply by X because you do not know if it is negative or positive.
Post by
Patty
You multiply by X to get rid of the X so you can work out an answer.
Dividing by X, you can't solve the question.
Post by
Toldry
See above comment.
Post by
Patty
You can. :)
The Xs cancel out, regardless of if they're negative or positive. Or...I think that's what we were taught. It was 2 years ago though D:
Edit: If it's negative, it would be shown as -x.
Post by
Toldry
No, you can not multiply by it because when you multiply a negative number in a unequal equation the '>' sign turns into '<'
And when you multiply by positive the sign doesn't change.
And because we don't know ifr X is negative or positive we can not multiply by it.
Post by
Patty
See: Edited bit.
If X was negative, it would be -x.
x is positive, because there is no minus sign. ;)
Post by
Toldry
>_>
X = -3
Is that possible?
Yes.
And if X = -3 then -X=3
Do you see where your logic is flawed now?
Post by
Patty
>_>
Forgot that bit.
As I said, it's been a long time.
:/
Um...just go with hyper's, because you'll probably get a mark for the working even if the answer is incorrect.
Post by
Toldry
No offense, but that error would be so clear that if I was seen doing it I might be sent to a lower level class of math.
I'm not serious, but you get the point.
Post by
Patty
...Why exactly would I be offended?
If you didn't know the answer, and got a reply on here, surely it's better than nothing.
Post by
Toldry
You're right.
D:
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