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What is the value of x? (1) x = 4. (2) x^2 = 16.
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11 May 2017, 10:56
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What is the value of x? (1) x = 4. (2) x^2 = 16. I want to know how B is not sufficient here. Isn't it a general rule that square root of any number is always positive?
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Re: What is the value of x? (1) x = 4. (2) x^2 = 16.
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11 May 2017, 11:10
ashikaverma13 wrote: What is the value of x?
(1) x = 4.
(2) x^2 = 16.
I want to know how B is not sufficient here. Isn't it a general rule that square root of any number is always positive? What is the value of x?(1) x = 4 > x = 4 or x = 4. Not sufficient. (2) x^2 = 16 > the same here: x = 4 or x = 4. Not sufficient. (1)+(2) Same two values from both: x = 4 or x = 4. Not sufficient. Answer: E. As for your question: when the GMAT provides the square root sign for an even root, such as \(\sqrt{x}\) or \(\sqrt[4]{x}\), then the only accepted answer is the positive root. That is, \(\sqrt{16}=4\), NOT +4 or 4. Even roots have only a positive value on the GMAT.In contrast, the equation \(x^2=16\) has TWO solutions, +4 and 4. Hope it's clear.
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What is the value of x? (1) x = 4. (2) x^2 = 16.
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11 May 2017, 13:12
Bunuel wrote: ashikaverma13 wrote: What is the value of x?
(1) x = 4.
(2) x^2 = 16.
I want to know how B is not sufficient here. Isn't it a general rule that square root of any number is always positive? What is the value of x?(1) x = 4 > x = 4 or x = 4. Not sufficient. (2) x^2 = 16 > the same here: x = 4 or x = 4. Not sufficient. (1)+(2) Same two values from both: x = 4 or x = 4. Not sufficient. Answer: E. As for your question: when the GMAT provides the square root sign for an even root, such as \(\sqrt{x}\) or \(\sqrt[4]{x}\), then the only accepted answer is the positive root. That is, \(\sqrt{16}=4\), NOT +4 or 4. Even roots have only a positive value on the GMAT.In contrast, the equation \(x^2=16\) has TWO solutions, +4 and 4. Hope it's clear. I think I understood but one more thing. So if, the statement B had said x = \(\sqrt{16}\) then it would have been sufficient? but what is the difference if I, on my own am taking a square root of the statement B. That is my confusion. If I take square root of the entire statement B then won't it be: \(\sqrt{x^2}\) = \(\sqrt{16}\) which, therefore, will lead to x =4? unless I am doing something wrong by taking square root of the entire statement.
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Re: What is the value of x? (1) x = 4. (2) x^2 = 16.
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11 May 2017, 20:44
ashikaverma13 wrote: Bunuel wrote: ashikaverma13 wrote: What is the value of x?
(1) x = 4.
(2) x^2 = 16.
I want to know how B is not sufficient here. Isn't it a general rule that square root of any number is always positive? What is the value of x?(1) x = 4 > x = 4 or x = 4. Not sufficient. (2) x^2 = 16 > the same here: x = 4 or x = 4. Not sufficient. (1)+(2) Same two values from both: x = 4 or x = 4. Not sufficient. Answer: E. As for your question: when the GMAT provides the square root sign for an even root, such as \(\sqrt{x}\) or \(\sqrt[4]{x}\), then the only accepted answer is the positive root. That is, \(\sqrt{16}=4\), NOT +4 or 4. Even roots have only a positive value on the GMAT.In contrast, the equation \(x^2=16\) has TWO solutions, +4 and 4. Hope it's clear. I think I understood but one more thing. So if, the statement B had said x = \(\sqrt{16}\) then it would have been sufficient? but what is the difference if I, on my own am taking a square root of the statement B. That is my confusion. If I take square root of the entire statement B then won't it be: \(\sqrt{x^2}\) = \(\sqrt{16}\) which, therefore, will lead to x =4? unless I am doing something wrong by taking square root of the entire statement. 1. \(\sqrt{16}\)=4 The square root of a negative number is not a real number and is not tested on the GMAT. 2. x^2 = 16 => x = 4 or 4 In this case , we have an exponent . If we square the number 4 , we get 16 . If we square the number  4 , we get 16 . Therefore, both numbers are possible values for x, because both make the equation true. 3. \(\sqrt{x^2}\) = \(\sqrt{16}\) Now squaring both sides, we get x^2 = 16 the above is same as case 2 , thus x can have 2 values > 4 and  4
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Re: What is the value of x? (1) x = 4. (2) x^2 = 16.
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25 Dec 2017, 20:51
ashikaverma13 wrote: What is the value of x?
(1) x = 4.
(2) x^2 = 16.
I want to know how B is not sufficient here. Isn't it a general rule that square root of any number is always positive? 1. Value of X can be +4 or 4 2. Value of X can be +4 or 4 as 4^2=16 and (4)^2=16 Both are giving 2 different values and hence none is sufficient . Answer: E
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Re: What is the value of x? (1) x = 4. (2) x^2 = 16.
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30 Dec 2017, 08:43
ashikaverma13 wrote: What is the value of x?
(1) x = 4.
(2) x^2 = 16.
I want to know how B is not sufficient here. Isn't it a general rule that square root of any number is always positive? (1) x = 4. (2) x^2 = 16. st 1: x means x =  4 or x = 4 as "x" shows the distance of "x" from "0" on the number line is "4". And distance is always >= 0 So st 1 is insufficient st 2: x^2 = 16 Value of exponent over the number shows the number of roots so, here "x" can take 2 values 4 & +4 So insufficient. combining 1 & 2 do not give us any single value so (E)
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Re: What is the value of x? (1) x = 4. (2) x^2 = 16.
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05 Apr 2018, 02:46
Bunuel wrote: ashikaverma13 wrote: What is the value of x?
(1) x = 4.
(2) x^2 = 16.
I want to know how B is not sufficient here. Isn't it a general rule that square root of any number is always positive? What is the value of x?(1) x = 4 > x = 4 or x = 4. Not sufficient. (2) x^2 = 16 > the same here: x = 4 or x = 4. Not sufficient. (1)+(2) Same two values from both: x = 4 or x = 4. Not sufficient. Answer: E. As for your question: when the GMAT provides the square root sign for an even root, such as \(\sqrt{x}\) or \(\sqrt[4]{x}\), then the only accepted answer is the positive root. That is, \(\sqrt{16}=4\), NOT +4 or 4. Even roots have only a positive value on the GMAT.In contrast, the equation \(x^2=16\) has TWO solutions, +4 and 4. Hope it's clear. isn't the root of x^2 = the absolute value of x therefore i thought you need to combine the ac...



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Re: What is the value of x? (1) x = 4. (2) x^2 = 16.
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05 Apr 2018, 02:49
gmatmo wrote: Bunuel wrote: ashikaverma13 wrote: What is the value of x?
(1) x = 4.
(2) x^2 = 16.
I want to know how B is not sufficient here. Isn't it a general rule that square root of any number is always positive? What is the value of x?(1) x = 4 > x = 4 or x = 4. Not sufficient. (2) x^2 = 16 > the same here: x = 4 or x = 4. Not sufficient. (1)+(2) Same two values from both: x = 4 or x = 4. Not sufficient. Answer: E. As for your question: when the GMAT provides the square root sign for an even root, such as \(\sqrt{x}\) or \(\sqrt[4]{x}\), then the only accepted answer is the positive root. That is, \(\sqrt{16}=4\), NOT +4 or 4. Even roots have only a positive value on the GMAT.In contrast, the equation \(x^2=16\) has TWO solutions, +4 and 4. Hope it's clear. isn't the root of x^2 = the absolute value of x therefore i thought you need to combine the ac... Yes, \(\sqrt{x^2}=x\). Could not understand what you mean after that.
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Collection of Questions: PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.
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Re: What is the value of x? (1) x = 4. (2) x^2 = 16.
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05 Apr 2018, 03:56
my question is because Root x^2 >x> x = 4 whats wrong with this assumption.



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Re: What is the value of x? (1) x = 4. (2) x^2 = 16.
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05 Apr 2018, 04:35




Re: What is the value of x? (1) x = 4. (2) x^2 = 16. &nbs
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