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605-655 Level|   Algebra|   Exponents|      
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Bunuel
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If y^(3x) = 5^x and y is a positive number, what is x? 24 Sep 2017, 23:56
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Difficulty:

45% (medium)

Question Stats:

65% (01:29) correct 35% (01:40) wrong based on 142 sessions

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If \(y^{(3x)} = 5^x\) and y is a positive number, what is x?


(1) \(y = \sqrt[3]{5}\)

(2) \(y^x=5^{(\frac{x}{3})}\)
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E
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Nikkb
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If y^(3x) = 5^x and y is a positive number, what is x? 25 Sep 2017, 03:03
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If \(y^{3x}=5^x\) and y is a positive number, what is x?

\(y^{3x}=5^x\)
=> \((y^3)^x=5^x\)
=> \(y^3=5\)
=> \(y=5^\frac{1}{3}\)

(1) \(y= \sqrt[3]5\)
=> \(y^3 = 5\)
This is already given in question stem. As no detail about x given.
Insufficient

(2) \(y^x=5^\frac{x}{3}\)
=> \(y^x=(5^\frac{1}{3})^x\)
=> \(y=5^\frac{1}{3}\)
This is already given in question stem. As no detail about x given.
Insufficient

1+2
Here also we don't get any information about x

Answer: E
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If y^(3x) = 5^x and y is a positive number, what is x? 26 Feb 2018, 10:00
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Nikkb
If \(y^{3x}=5^x\) and y is a positive number, what is x?

\(y^{3x}=5^x\)
=> \((y^3)^x=5^x\)
=> \(y^3=5\)
=> \(y=5^\frac{1}{3}\)

(1) \(y= \sqrt[3]5\)
=> \(y^3 = 5\)
This is already given in question stem. As no detail about x given.
Insufficient

(2) \(y^x=5^\frac{x}{3}\)
=> \(y^x=(5^\frac{1}{3})^x\)
=> \(y=5^\frac{1}{3}\)
This is already given in question stem. As no detail about x given.
Insufficient

1+2
Here also we don't get any information about x

Answer: E
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Why can't we use the information given in the statement 1 and substitute it in the stem "y"??
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If y^(3x) = 5^x and y is a positive number, what is x? 26 Feb 2018, 10:45
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sahilsnpt
Nikkb
If \(y^{3x}=5^x\) and y is a positive number, what is x?

\(y^{3x}=5^x\)
=> \((y^3)^x=5^x\)
=> \(y^3=5\)
=> \(y=5^\frac{1}{3}\)

(1) \(y= \sqrt[3]5\)
=> \(y^3 = 5\)
This is already given in question stem. As no detail about x given.
Insufficient

(2) \(y^x=5^\frac{x}{3}\)
=> \(y^x=(5^\frac{1}{3})^x\)
=> \(y=5^\frac{1}{3}\)
This is already given in question stem. As no detail about x given.
Insufficient

1+2
Here also we don't get any information about x

Answer: E
Why can't we use the information given in the statement 1 and substitute it in the stem "y"??
Show more

Hi sahilsnpt

our objective is to find the value of x and as explained in the above solution both statement 1 & the question stem gives the same information. So it will not lead to any solution. Just for practice, try substituting the value of y from statement 1 in the question stem and see if you are getting any value for x
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sahilsnpt
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If y^(3x) = 5^x and y is a positive number, what is x? 27 Feb 2018, 12:15
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niks18
sahilsnpt
Nikkb
If \(y^{3x}=5^x\) and y is a positive number, what is x?

\(y^{3x}=5^x\)
=> \((y^3)^x=5^x\)
=> \(y^3=5\)
=> \(y=5^\frac{1}{3}\)

(1) \(y= \sqrt[3]5\)
=> \(y^3 = 5\)
This is already given in question stem. As no detail about x given.
Insufficient

(2) \(y^x=5^\frac{x}{3}\)
=> \(y^x=(5^\frac{1}{3})^x\)
=> \(y=5^\frac{1}{3}\)
This is already given in question stem. As no detail about x given.
Insufficient

1+2
Here also we don't get any information about x

Answer: E
Why can't we use the information given in the statement 1 and substitute it in the stem "y"??

Hi sahilsnpt

our objective is to find the value of x and as explained in the above solution both statement 1 & the question stem gives the same information. So it will not lead to any solution. Just for practice, try substituting the value of y from statement 1 in the question stem and see if you are getting any value for x
Show more
No,I am not getting any solution of X.Thank you for the explanation!
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