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Re: \sqrt{7 + \sqrt{48}} - \sqrt{3} = ? [#permalink]
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If some1 is really fast in calculation then they might try this method as well.

\(\sqrt{ 7+ \sqrt{48}} - \sqrt{3}\) = \(\sqrt{ 14} - \sqrt{3}\) ( approximating 48 as 49)

= 3.7xxx - 1.732

which is close to 2.

but looking at the question it is better to do it the way Bunuel did it as GMAT doesn't want us to be good at calculations but at observation.
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Re: \sqrt{7 + \sqrt{48}} - \sqrt{3} = ? [#permalink]
Bunuel wrote:
faiint wrote:
sqrt{7 + \sqrt{48}} - \sqrt{3} = ?

How come we can't do {sqrt{7 + \sqrt{48}} }^2 = {\sqrt{3}}^2 to solve?


Can you please elaborate what you mean? Thank you.

\(\sqrt{7 + \sqrt{48}} - \sqrt{3} = ?\)

A. 1
B. 1.7
C. 2
D. 2.4
E. 3

The expression \(7 + \sqrt{48}\) can be rewritten as \(4 + 4\sqrt{3}+3\) which is the same as \((2+\sqrt{3})^2\). Therefore, \(\sqrt{7 + \sqrt{48}} - \sqrt{3} = (2+\sqrt{3})-\sqrt{3}=2\).

Answer: C.

P.S. Please read carefully and follow: rules-for-posting-please-read-this-before-posting-133935.html Pay attention to rules 2, 3, 7, 8, 9 and 10. Thank you.



can anyone show me how we reduced( 2+sqrt3)^2-sqrt3 to become just (2+sqrt3)-sqrt3
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Re: \sqrt{7 + \sqrt{48}} - \sqrt{3} = ? [#permalink]
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23a2012 wrote:
Bunuel wrote:
faiint wrote:
sqrt{7 + \sqrt{48}} - \sqrt{3} = ?

How come we can't do {sqrt{7 + \sqrt{48}} }^2 = {\sqrt{3}}^2 to solve?


Can you please elaborate what you mean? Thank you.

\(\sqrt{7 + \sqrt{48}} - \sqrt{3} = ?\)

A. 1
B. 1.7
C. 2
D. 2.4
E. 3

The expression \(7 + \sqrt{48}\) can be rewritten as \(4 + 4\sqrt{3}+3\) which is the same as \((2+\sqrt{3})^2\). Therefore, \(\sqrt{7 + \sqrt{48}} - \sqrt{3} = (2+\sqrt{3})-\sqrt{3}=2\).

Answer: C.

P.S. Please read carefully and follow: rules-for-posting-please-read-this-before-posting-133935.html Pay attention to rules 2, 3, 7, 8, 9 and 10. Thank you.



can anyone show me how we reduced( 2+sqrt3)^2-sqrt3 to become just (2+sqrt3)-sqrt3


\(\sqrt{7 + \sqrt{48}} - \sqrt{3} =\sqrt{(2+\sqrt{3})^2} - \sqrt{3}= (2+\sqrt{3})-\sqrt{3}=2\)
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Re: \sqrt{7 + \sqrt{48}} - \sqrt{3} = ? [#permalink]
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faiint wrote:
\(\sqrt{7 + \sqrt{48}} - \sqrt{3} = ?\)

A. 1
B. 1.7
C. 2
D. 2.4
E. 3

M11-18


\(sqrt{48}\) is approximately 7; \(\sqrt{7 + \sqrt{48}\) falls between 3 and 4, say 3,7d \(sqrt{3}\) is approximately 1,7; result is very close to 2. A & B too small D & E too big C = correct.
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Re: \sqrt{7 + \sqrt{48}} - \sqrt{3} = ? [#permalink]
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√of 48 =6.9 so we make it 49. √7+7 -√3 = √14 -√3= 3.7-1.5= 2 (C)
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Re: \sqrt{7 + \sqrt{48}} - \sqrt{3} = ? [#permalink]
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faiint wrote:
\(\sqrt{7 + \sqrt{48}} - \sqrt{3} = ?\)

A. 1
B. 1.7
C. 2
D. 2.4
E. 3

M11-18


\(\sqrt{7 + \sqrt{48}} - \sqrt{3} = ?\)
\(\sqrt{4 +3 + 2 \sqrt{4*3}} - \sqrt{3} = \sqrt{4} + \sqrt{3} -\sqrt{3} =\sqrt{4} =2\)

IMO C
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Re: \sqrt{7 + \sqrt{48}} - \sqrt{3} = ? [#permalink]
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Re: \sqrt{7 + \sqrt{48}} - \sqrt{3} = ? [#permalink]
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