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30 Mar 2020, 09:28
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D
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
35%
(medium)
Question Stats:
70% (01:50) correct
30%
(02:24)
wrong
based on 60
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Not Attempted Yet
If \(3^{4x} = 8100\), what is the value of \((3^{x-1})^2\)?
A. 900
B. 90
C. 30
D. 10
E. 10/3
Posted from my mobile device
A. 900
B. 90
C. 30
D. 10
E. 10/3
Posted from my mobile device
30 Mar 2020, 09:33
Kudos
Bookmarks
Dillesh4096
If \(3^{4x} = 8100\), what is the value of \((3^{x-1})^2\)?
A. 900
B. 90
C. 30
D. 10
E. 10/3
Posted from my mobile device
A. 900
B. 90
C. 30
D. 10
E. 10/3
Posted from my mobile device
Given: \(3^{4x} = 8100\)
Taking square root both sides
\(3^{2x} = √8100 = 90\)
\((3^{x-1})^2 = 3^{2x-2} = \frac{3^{2x}}{3^2} = \frac{√8100 }{ 9} = \frac{90}{9} = 10\)
Answer: Option D
ArunSharma12
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30 Mar 2020, 09:39
Kudos
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Dillesh4096
If \(3^{4x} = 8100\), what is the value of \((3^{x-1})^2\)?
A. 900
B. 90
C. 30
D. 10
E. 10/3
A. 900
B. 90
C. 30
D. 10
E. 10/3
\(3^{4x} = 8100\)
\(3^{4x} = 3^4*(10)^2\);take \(3^4\) to Left side in the denominator and simplify
\(3^{4x-4} = (10)^2\)
\(3^{4(x-1)} = (10)^2\)
\((3^{(x-1)})^4 = (10)^2\); take square root of both sides
\((3^{(x-1)})^2 = 10\)
Ans: D
