[Winch2012]

Heya, im doing a past paper for the exam on Monday, it's a non calculator and I am stuck on a similar sort of question.



What I did was:



I multiplied out the numerator and then cross multiplied the denominator onto the other side of the equals sign:






Here is where i got stuck..
I had to options, either follow what Mathswatch had taught me and rearrange the whole equation to make 0 then factorise or use the quadratic formula..
Since this is a non calculator i attempted the rearranging and factorising:



I tried the ABC method ( a=2 .. b= -21 .. c= 37)
The rule is which would in this case
The factors of 74 are : 1 and 74, 2 and 37 and neither of these add or subtract to make B which is -21..

So I'm either lost, over complicating things or completely wrong!
Please, can someone help me?

[The Polymath]

(Original post by Winch2012)
Heya, im doing a past paper for the exam on Monday, it's a non calculator and I am stuck on a similar sort of question.



What I did was:



I multiplied out the numerator and then cross multiplied the denominator onto the other side of the equals sign:






Here is where i got stuck..
I had to options, either follow what Mathswatch had taught me and rearrange the whole equation to make 0 then factorise or use the quadratic formula..
Since this is a non calculator i attempted the rearranging and factorising:



I tried the ABC method ( a=2 .. b= -21 .. c= 37)
The rule is which would in this case
The factors of 74 are : 1 and 74, 2 and 37 and neither of these add or subtract to make B which is -21..

So I'm either lost, over complicating things or completely wrong!
Please, can someone help me?

I believe you're right - there's no simple solution, and you'd just have to give it in terms of the quadratic formula. http://www.wolframalpha.com/input/?i...%29%5E-1+%3D+2
My calculator came out with a solution of 8.26.... so yeah, there's no simple solution

Edit: Wolfram Alpha - the most amazing maths tool on the internet it's soo good

[ThatPerson]

(Original post by Junaid96)
I believe you're right - there's no simple solution, and you'd just have to give it in terms of the quadratic formula. http://www.wolframalpha.com/input/?i...%29%5E-1+%3D+2
My calculator came out with a solution of 8.26.... so yeah, there's no simple solution

Edit: Wolfram Alpha - the most amazing maths tool on the internet it's soo good

The question was non-calculator.

[Winch2012]

Yeah however, the mark scheme says that X = 5 or X = -0.5

The brief explanation is:
M1 for common denominator on LHS or clearing fractions
M1 for multiplying out brackets
A1 for
M1 for (2x ± 1)(x ± 5) or substitution into quadratic formula
A1 for 5 and - 0.5

[Icedstoat]

(Original post by ThatPerson)
The question was non-calculator.

True, but that doesn't stop you using the formula:
(21+Sqrt137)/4 or (21-Sqrt137)/4 being the solutions as I get them

[The Polymath]

(Original post by ThatPerson)
The question was non-calculator.

Yes, I know. I just used a calculator to confirm my suspicions.

(Original post by Icedstoat)
True, but that doesn't stop you using the formula:
(21+Sqrt137)/4 or (21-Sqrt137)/4 being the solutions as I get them

Yep, and as I said in my OP, "you'd just have to give it in terms of the quadratic formula"

(Original post by Winch2012)
Yeah however, the mark scheme says that X = 5 or X = -0.5

The brief explanation is:
M1 for common denominator on LHS or clearing fractions
M1 for multiplying out brackets
A1 for
M1 for (2x ± 1)(x ± 5) or substitution into quadratic formula
A1 for 5 and - 0.5

but.. 5 isn't a solution?

[raheem94]

(Original post by Junaid96)
...

(Original post by Icedstoat)
...

(Original post by Winch2012)
Yeah however, the mark scheme says that X = 5 or X = -0.5

The brief explanation is:
M1 for common denominator on LHS or clearing fractions
M1 for multiplying out brackets
A1 for
M1 for (2x ± 1)(x ± 5) or substitution into quadratic formula
A1 for 5 and - 0.5

(Original post by ThatPerson)
...

There is a typo.

The question should be

The minus sign should be positive.

[Icedstoat]

OP, if that's the mark scheme, then you've probably misread the question or something.

[raheem94]

(Original post by Icedstoat)
OP, if that's the mark scheme, then you've probably misread the question or something.

See my previous post.

[Icedstoat]

Yeah, I really need to learn to type faster before someone else says what I'm about to say

[Winch2012]

THANKS SO MUCH!
I literally spent hours on this question !!