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# If (√a − √b)(√a + √b) = 12, then what is a in terms of b?

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Math Expert
Joined: 02 Sep 2009
Posts: 58396
If (√a − √b)(√a + √b) = 12, then what is a in terms of b?  [#permalink]

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22 Jan 2019, 00:47
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Difficulty:

15% (low)

Question Stats:

89% (00:45) correct 11% (01:43) wrong based on 24 sessions

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If (√a − √b)(√a + √b) = 12, then what is a in terms of b?

A b + 12
B b^2 + 12
C √b + 12
D √b + √12
E √b – √12

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Joined: 31 Oct 2013
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Concentration: Accounting, Finance
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Re: If (√a − √b)(√a + √b) = 12, then what is a in terms of b?  [#permalink]

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22 Jan 2019, 00:55
Bunuel wrote:
If (√a − √b)(√a + √b) = 12, then what is a in terms of b?

A b + 12
B b^2 + 12
C √b + 12
D √b + √12
E √b – √12

Given

(√a − √b)(√a + √b) = 12

$$(√a)^2 - (√b)^2 =12$$

a - b =12

a = 1 +12.

A is the correct answer.
Re: If (√a − √b)(√a + √b) = 12, then what is a in terms of b?   [#permalink] 22 Jan 2019, 00:55
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# If (√a − √b)(√a + √b) = 12, then what is a in terms of b?

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