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OG Problem- number 225 Problem Solving on page 183

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OG Problem- number 225 Problem Solving on page 183

by jaydeer44 » Sun May 18, 2008 4:04 pm
Can someone please help explain this problem? I see that the answer is A, but I don't understand OG's explanation. They plug in the (1/x) into the equation, go through some complicated crossing out and simplifying, and finally arrive back at the original equation presented in the problem.

Is all that work even necessary? I don't understand why the answer wouldn't simply be A, regardless of what you substitute in for "x".
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by dextar » Sun May 18, 2008 10:13 pm
Hi dude
From ur point, I can get that u want to ask y the answer won't be A regardless of what u substitute.

So simply puit x=-x and c whether u can get the same expression
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by moneyman » Mon May 19, 2008 6:13 am
Ok here it goes

Just substitute the 1/x for x and solve for the answer

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

= [(1/x)^2 + 2 * 1/x * 1 + (1)^2] / [(1/x)^2 - 2 * 1/x * 1 + (1)^2]

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

Cancel the common denominators to get

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

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

Hope it helps!!
Maxx
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