R = ?

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R = ?

by AbeNeedsAnswers » Mon Jul 03, 2017 8:39 pm

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A

B

C

D

E

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If p ≠ 0 and p - (1-p^2)/p = r/p, then r =

A) p + 1

B) 2p - 1

C) p^2+ 1

D) 2p^2 - 1

E) p^2 + p - 1

D

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by GMATGuruNY » Mon Jul 03, 2017 9:18 pm
AbeNeedsAnswers wrote:If p ≠ 0 and p - (1-p^2)/p = r/p, then r =

A) p + 1

B) 2p - 1

C) p^2+ 1

D) 2p^2 - 1

E) p^2 + p - 1
Let p=-1.

Substituting p=-1 into p - (1-p²)/p = r/p, we get:
-1 - [1 - (-1)²]/-1 = r/(-1)
-1 - 0 = -r
-1 = -r
r = 1.

Since the question stem asks for the value of r, our target value is r=1.
Now plug p=-1 into the answers to see which yields our target value of 1.
Only D works:
2p² - 1 = 2(-1)² - 1 = 1.

The correct answer is D.
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by Jay@ManhattanReview » Mon Jul 03, 2017 9:26 pm
AbeNeedsAnswers wrote:If p ≠ 0 and p - (1-p^2)/p = r/p, then r =

A) p + 1

B) 2p - 1

C) p^2+ 1

D) 2p^2 - 1

E) p^2 + p - 1

D
We have p - (1-p^2)/p = r/p

=> [p^2 -(1-p^2)]/p = r/p; taking LCM of LHS

Since p ≠ 0, we can cancel p from both the sides.

=> p^2 -(1-p^2) = r

=> r = p^2 -1 + p^2

[spoiler]r = 2p^2 -1[/spoiler]

The correct answer: D

Hope this helps!

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by ceilidh.erickson » Tue Jul 04, 2017 8:12 am
p - (1 - p²)/p = r/p

Start by multiplying both sides by p:
p[p - (1 - p²)/p = r/p]
p² - (1 - p²) = r
p² - 1 + p² = r
2p² - 1 = r

The answer is D.
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by Matt@VeritasPrep » Wed Jul 05, 2017 1:01 am
p - (1 - p²)/p = r/p

multiply both sides by p:

p² - (1 - p²) = r

do the subtraction on the left side:

2p² - 1 = r

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by Scott@TargetTestPrep » Wed Jul 12, 2017 4:27 pm
AbeNeedsAnswers wrote:If p ≠ 0 and p - (1-p^2)/p = r/p, then r =

A) p + 1

B) 2p - 1

C) p^2+ 1

D) 2p^2 - 1

E) p^2 + p - 1
Let's simplify the given equation p - (1-p^2)/p = r/p by multiplying both sides by p:

p^2 - (1-p^2) = r

p^2 - 1 + p^2 = r

2p^2 - 1 = r

Answer: D

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by [email protected] » Sat Jun 09, 2018 5:57 pm
Hi All,

We're told that P ≠ 0 and P - (1 - P^2)/P = R/P. We're asked for the value of R. This question can be solved in a couple of different ways, including by TESTing VALUES.

IF....P=2, then we have....

2 - [(1 - 4)/2] = R/2
2 - ( -3/2) = R/2
4/2 - (-3/2) = R/2
7/2 = R/2
7 = R

So we're looking for an answer that equals 7 when P=2. There's only one answer that matches...

Final Answer: D

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