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# Maths help - them tricky, TRICKY algebra questions. (not for the faint hearted)

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Why bother with a post grad? Are they even worth it? Have your say! 26-10-2016
1. Alright, here it is:

7/x+2 + 1/x-1 = 4

I got ONE. Photomath told me the answer was -1/2. I don't understand why. I don't understand how.

I used to be an algebra genius, but my powers appear to be failing me. If anyone could help, it would be greatly appreciated - thanks.
2. (Original post by ZiggyStarDust_)
Alright, here it is:

7/x+2 + 1/x-1 = 4

I got ONE. Photomath told me the answer was -1/2. I don't understand why. I don't understand how.

I used to be an algebra genius, but my powers appear to be failing me. If anyone could help, it would be greatly appreciated - thanks.
I LOVE ALGEBRA. I will test it to see.
3. It's -1/2 or 3/2. Just cross multiply the denominators so you get a single fraction with a quadratic denominator. Then multiply the right of the equals sign by the quadratic, and solve it as you would a normal quadratic.
4. ooooh that looks tricky ill have a go
5. did you mean

7/(x+2) + 1/(x-1) = 4

?

6. (Original post by aidanjt)
It's -1/2 or 3/2. Just cross multiply the denominators so you get a single fraction with a quadratic denominator. Then multiply the right of the equals sign by the quadratic, and solve it as you would a normal quadratic.
Yeah that's what I got.
7. (Original post by the bear)
did you mean

7/(x+2) + 1/(x-1) = 4

?

yep
8. (Original post by Math12345)

okay, thank you for this

this makes more sense!

9. Alright so this is my working:

-7/(x+2) + 1/(x-1)=4

-Cross multiply to get:
[7(x-1)+1(x+2)]/(x-1)(x+2)=4
-Expand brackets to get:
(7x-7+x+2)/(x^2+2x-x-2)=4
-Simplify further to get:
(8x-5)/(x^2+x-2)=4
-Bring denominator to the top to get:
(8x-5)=4(x^2+x-2)
-Expand brackets to form a quadratic equation:
4x^2-4x-3=0
(2x+1)(2x-3)=0
At which point you should have two solutions, x=-1/2 and x=3/2

Hope this can help I love algebra too!! (And any form of math, really).

Edit: oops, looks like I was a bit too late to the party
10. x = -1/2 and x = 3/2

You could factorise or use quadratic formula whichever you prefer later in the question.

Would you like detailed explanation ?
11. (Original post by Chlktrain135)

Alright so this is my working:

-7/(x+2) + 1/(x-1)=4

-Cross multiply to get:
[7(x-1)+1(x+2)]/(x-1)(x+2)=4
-Expand brackets to get:
(7x-7+x+2)/(x^2+2x-x-2)=4
-Simplify further to get:
(8x-5)/(x^2+x-2)=4
-Bring denominator to the top to get:
(8x-5)=4(x^2+x-2)
-Expand brackets to form a quadratic equation:
4x^2-4x-3=0
(2x+1)(2x-3)=0
At which point you should have two solutions, x=-1/2 and x=3/2

Hope this can help I love algebra too!! (And any form of math, really).

Edit: oops, looks like I was a bit too late to the party
Haha, no that's okay

This is still a useful answer actually, because you explained the steps.

so thank you ! (:
12. here's one nice algebra question http://prntscr.com/b6fl58
13. (Original post by _Xenon_)
x = -1/2 and x = 3/2

You could factorise or use quadratic formula whichever you prefer later in the question.

Would you like detailed explanation ?
the quadratic formula is my main bae, i'll definitely use that in the future

Nope, that's okay I think I'm on track for this question now, but thank you! :-)
14. (Original post by Math12345)

yeah i got this too
15. (Original post by ihatehannah)
here's one nice algebra question http://prntscr.com/b6fl58

I'll explain the first to second step: . The rest are just indice rules
16. (Original post by ZiggyStarDust_)
the quadratic formula is my main bae, i'll definitely use that in the future

Nope, that's okay I think I'm on track for this question now, but thank you! :-)
No problem and yeah same I love to use the quadratic formula too for these questions!
Btw which exam board are you with?
17. (Original post by _Xenon_)
No problem and yeah same I love to use the quadratic formula too for these questions!
Btw which exam board are you with?
I'm with edexcel - a pretty fair exam board, from what I've seen

18. (Original post by ZiggyStarDust_)
I'm with edexcel - a pretty fair exam board, from what I've seen

Edexcel IGCSE.
19. Why is this tricky?

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