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If 8*3^7 = 3^x - 3^(x - 2), what is the value of x?
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15 May 2022, 22:46
15 May 2022, 22:46
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Question Stats:
83% (01:51) correct
16% (01:39) wrong based on 12 sessions
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If \(8*3^7 = 3^x - 3^{x-2}\), what is the value of x?
A. 1
B. 3
C. 7
D. 9
E. 12
A. 1
B. 3
C. 7
D. 9
E. 12
Part of the project: GRE QCQ & PS 3 Questions Every One DAILY Challenge - (2022)
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GRE Math Essentials for a TOP Quant Score - Q170!!! (2021)
GRE Geometry Formulas for a Q170
GRE - Math Book
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
GRE Math Essentials for a TOP Quant Score - Q170!!! (2021)
GRE Geometry Formulas for a Q170
GRE - Math Book
If 8*3^7 = 3^x - 3^(x - 2), what is the value of x?
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16 May 2022, 03:32
16 May 2022, 03:32
1
\(8*3^7 = 3^x - 3^{x-2}\)
\(8 * 3^7 = 3^x - \frac{3^x}{9}\)
Multiplying both the sides with \(9\)
\(9 * 8 * 3^7 = 9 * 3^x - 3^x\)
\(3^{2+7} = 3^x\)
\(x = 9\)
Answer \(D\)
\(8 * 3^7 = 3^x - \frac{3^x}{9}\)
Multiplying both the sides with \(9\)
\(9 * 8 * 3^7 = 9 * 3^x - 3^x\)
\(3^{2+7} = 3^x\)
\(x = 9\)
Answer \(D\)
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Re: If 8*3^7 = 3^x - 3^(x - 2), what is the value of x?
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16 May 2022, 06:18
16 May 2022, 06:18
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Carcass wrote:
If \(8*3^7 = 3^x - 3^{x-2}\), what is the value of x?
A. 1
B. 3
C. 7
D. 9
E. 12
A. 1
B. 3
C. 7
D. 9
E. 12
Given: \((8)(3^7) = 3^x - 3^{x-2}\)
Factor the right side: \((8)(3^7) = 3^{x-2}(3^2 - 1)\)
Evaluate the part in brackets: \((8)(3^7) = 3^{x-2}(8)\)
Divide both sides of the equation by \(8\) to get: \(3^7 = 3^{x-2}\)
Since the bases are equal, we know that \(7 = x-2\), which means \(x = 9\)
Answer: D
