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What is the value of 2x^2  2.4x  1.7 for x = 0.7 ? [#permalink]
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03 Mar 2014, 01:16
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The Official Guide For GMAT® Quantitative Review, 2ND EditionWhat is the value of \(2x^2  2.4x  1.7\) for \(x = 0.7\) ? (A) 0.72 (B) 1.42 (C) 1.98 (D) 2.40 (E) 2.89 Problem Solving Question: 121 Category: Algebra Simplifying algebraic expressions Page: 77 Difficulty: 600 GMAT Club is introducing a new project: The Official Guide For GMAT® Quantitative Review, 2ND Edition  Quantitative Questions ProjectEach week we'll be posting several questions from The Official Guide For GMAT® Quantitative Review, 2ND Edition and then after couple of days we'll provide Official Answer (OA) to them along with a slution. We'll be glad if you participate in development of this project: 1. Please provide your solutions to the questions; 2. Please vote for the best solutions by pressing Kudos button; 3. Please vote for the questions themselves by pressing Kudos button; 4. Please share your views on difficulty level of the questions, so that we have most precise evaluation. Thank you!
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Re: What is the value of 2x^2  2.4x  1.7 for x = 0.7 ? [#permalink]
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Updated on: 14 Jul 2014, 21:23
Answer = D = 2.4 \(2x^2  12.4x  1.7\) \(2x(x  1.2)  1.7\) Placing the value x = 0.7 2 . 0.7 (0.5)  1.7 0.7  1.7 = 2.4
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Originally posted by PareshGmat on 03 Mar 2014, 02:33.
Last edited by PareshGmat on 14 Jul 2014, 21:23, edited 2 times in total.




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Re: What is the value of 2x^2  2.4x  1.7 for x = 0.7 ? [#permalink]
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03 Mar 2014, 01:16



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Re: What is the value of 2x^2  2.4x  1.7 for x = 0.7 ? [#permalink]
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03 Mar 2014, 20:08
[2(7)(7)24(7)170]/100 =2.4 D
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Re: What is the value of 2x^2  2.4x  1.7 for x = 0.7 ? [#permalink]
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03 Mar 2014, 21:37
2(0.7)^2  2.4(0.7)  1.7 = 2(0.49)  1.68  1.7 = 0.98  1.68  1.7 = 2.4
Ans is (D)



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Re: What is the value of 2x^2  2.4x  1.7 for x = 0.7 ? [#permalink]
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04 May 2015, 13:30
2*49*10^(2)  24*7*10^(2)  170*10^(2) = 240*10^(2) = 2,4 Update \(x(2x2,4)1,7 = 0,7(1,42,4)1,7 = 0,71,7=2,4\)
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Re: What is the value of 2x^2  2.4x  1.7 for x = 0.7 ? [#permalink]
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06 May 2016, 08:25
Bunuel wrote: The Official Guide For GMAT® Quantitative Review, 2ND EditionWhat is the value of 2x^2  2.4x  1.7 for x = 0.7 ? (A) 0.72 (B) 1.42 (C) 1.98 (D) 2.40 (E) 2.89 Problem Solving Question: 121 Category: Algebra Simplifying algebraic expressions Page: 77 Difficulty: 600 GMAT Club is introducing a new project: The Official Guide For GMAT® Quantitative Review, 2ND Edition  Quantitative Questions ProjectEach week we'll be posting several questions from The Official Guide For GMAT® Quantitative Review, 2ND Edition and then after couple of days we'll provide Official Answer (OA) to them along with a slution. We'll be glad if you participate in development of this project: 1. Please provide your solutions to the questions; 2. Please vote for the best solutions by pressing Kudos button; 3. Please vote for the questions themselves by pressing Kudos button; 4. Please share your views on difficulty level of the questions, so that we have most precise evaluation. Thank you! \(2x^2\)  \(2.4x\)  1.7 ; given x = 0.7 Or, \(2(0.7)^2\)  \(2.4(0.7)\)  \(1.7\) Or, \(2(0.49)\)  \(2.4(0.7)\)  \(1.7\) Or, \(0.98\)  \(1.68\)  \(1.7\) Or, \( 2.40\) Hence answer will be (D)
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Re: What is the value of 2x^2  2.4x  1.7 for x = 0.7 ? [#permalink]
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06 May 2016, 09:55
[quote="Bunuel"] The Official Guide For GMAT® Quantitative Review, 2ND EditionWhat is the value of 2x^2  2.4x  1.7 for x = 0.7 ? (A) 0.72 (B) 1.42 (C) 1.98 (D) 2.40 (E) 2.89 2*0.7*0.72.4*0.71.7 .981.681.7 =2. 40 answer D



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Re: What is the value of 2x^2  2.4x  1.7 for x = 0.7 ? [#permalink]
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28 May 2016, 11:04
\(2 * \frac{7}{10}* \frac{7}{10} 2.4 * \frac{7}{10} 1.7\)
= \(\frac{49}{50}  2.4 * 10 *\frac{7}{10 * 10} 1.7 * \frac{10}{10}\)
= \(\frac{49}{50}  24 *\frac{7}{100} \frac{17}{10}\)
= \(\frac{49}{50}  \frac{42}{25}  \frac{17}{10}\)
=\(\frac{98168170}{100}\)
= 2.4 =Answer D.



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Re: What is the value of 2x^2  2.4x  1.7 for x = 0.7 ? [#permalink]
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26 Jul 2017, 16:42
Quote: What is the value of \(2x^2  2.4x  1.7\) for \(x = 0.7\) ?
(A) 0.72 (B) 1.42 (C) 1.98 (D) 2.40 (E) 2.89
Substituting 0.7 for x, we have: 2(0.7)^2  2.4(0.7)  1.7 2(0.49)  1.68  1.7 = 0.98  1.68  1.7 = 2.4 Alternate Solution: Let’s factor the expression 2x^2  2.4x  1.7: 2x^2  2.4x  1.7 = (x  1.7)(2x + 1) Now, substituting x = 0.7 in the factored expression, we get (0.7  1.7)(2(0.7) + 1) = (1)(1.4 + 1) = 2.4. Answer: D
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Re: What is the value of 2x^2  2.4x  1.7 for x = 0.7 ? [#permalink]
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25 Dec 2017, 05:00
Bunuel wrote: The Official Guide For GMAT® Quantitative Review, 2ND EditionWhat is the value of \(2x^2  2.4x  1.7\) for \(x = 0.7\) ? (A) 0.72 (B) 1.42 (C) 1.98 (D) 2.40 (E) 2.89 Problem Solving Question: 121 Category: Algebra Simplifying algebraic expressions Page: 77 Difficulty: 600 GMAT Club is introducing a new project: The Official Guide For GMAT® Quantitative Review, 2ND Edition  Quantitative Questions ProjectEach week we'll be posting several questions from The Official Guide For GMAT® Quantitative Review, 2ND Edition and then after couple of days we'll provide Official Answer (OA) to them along with a slution. We'll be glad if you participate in development of this project: 1. Please provide your solutions to the questions; 2. Please vote for the best solutions by pressing Kudos button; 3. Please vote for the questions themselves by pressing Kudos button; 4. Please share your views on difficulty level of the questions, so that we have most precise evaluation. Thank you! 2x^22.4x1.7 => x(2x2.4)+1.7 => substituting x=0.7 => 0.7(2*0.72.4)+1.7 => 0.7(1.42.4)+1.7 => 0.7(1)+1.7 => 0.71.7 => 2.4 Therefore 'D' Thanks Dinesh




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