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Prove that:
(x + 2)/x - (x-1)/(x+1) = 2(2x + 1)/x(x+1)

Method

2007-05-14 06:55:03 · 6 answers · asked by Nightmare! 2 in Science & Mathematics Mathematics

Lol im not bad at maths. Not the greatest either. Just struggle on harder questions...

2007-05-14 07:06:53 · update #1

6 answers

The lowest common denominator is x(x+1)

So, multiply the first term (x+2)/x by (x+1)/(x+1) This results in (x+2)(x+1)/x(x+1).

Now, multiply the second term (x-1)/(x+1) by x/x. This results in x(x-1)/x(x+1)

So adding together you get:

((x+2)(x+1) - x(x-1))/x(x+1)

Now, multiply out the terms = (x^2+3x+2-x^2+x)/x(x+1)

That simplifies to: 4x+2/x(x+1)

Now, factor out a 2 in the numerator, and you get:

2(2x+1)/x(x+1) which is what you wanted.

2007-05-14 07:05:46 · answer #1 · answered by Anonymous · 0 0

Rewrite the LHS as a single fraction, using the LCM: x(x + 1).
[(x + 2)(x + 1) - x(x - 1)] / [x(x + 1)] =
[x^2 + 3x + 2 - x^2 + x] / [x(x + 1)] =
[4x + 2] / [x(x + 1)] =
[2(2x + 1)] / [x(x + 1)].

2007-05-14 07:04:28 · answer #2 · answered by Darlene 4 · 0 0

OK, you need to make both parts of the left side of the equal sign be over the same denominator: x(x+1)

(x+2)/x = (x+1)(x+2)/x(x+1) Agreed?

(x-1)/(x+1) = x(x-1)/x(x+1) Agreed?

And so on...

2007-05-14 07:09:38 · answer #3 · answered by ? 7 · 0 0

LHS
[ (x + 2)(x + 1) - x.(x - 1) ] / [ x.(x + 1) ]
(x² + 3x + 2 - x² + x) / [ x.(x + 1) ]
(4x + 2) / [ x.(x + 1) ]
2.(2x + 1) / [ x.(x + 1) ] = RHS

2007-05-14 20:03:17 · answer #4 · answered by Como 7 · 0 0

(x + 2)/x - (x-1)/(x+1)

=([x+2)(x+1) - x(x-1)]/x.(x+1)

= (x^2+3x+2-x^2+x)/x.(x+1)
= (4x+2)/x.(x+1)
=2(2x+1)/x(x+1) q.e.d

2007-05-14 07:00:12 · answer #5 · answered by welcome news 6 · 0 0

76

2007-05-14 07:02:39 · answer #6 · answered by Diablo 3 · 0 2

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