Which of the following is equal to 2^k*5^(k-1)?
A. 2*10^(k-1)
B. 5*10^(k-1)
C. 10^k
D. 2*10^k )
E. 10^(2k-1)
The OA is A.
How can I rewrite the given expression to get A? I need your help experts. Please. Thanks in advance.
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Which of the following is equal to 2^k*5^(k-1)?
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EconomistGMATTutor
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Hello Vincen.
Let's rewrite the expression as follows $$2^k\cdot5^{k-1}=2\cdot2^{k-1}\cdot5^{k-1}=2\cdot\left(2\cdot5\right)^{k-1}=2\cdot10^{k-1}.$$ This tell us that the correct answer is A.
I hope this can help you to clarify your doubt.
I'm available if you'd like a follow up.
Regards.
Let's rewrite the expression as follows $$2^k\cdot5^{k-1}=2\cdot2^{k-1}\cdot5^{k-1}=2\cdot\left(2\cdot5\right)^{k-1}=2\cdot10^{k-1}.$$ This tell us that the correct answer is A.
I hope this can help you to clarify your doubt.
I'm available if you'd like a follow up.
Regards.
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Scott@TargetTestPrep
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Let's simplify the given expression:Vincen wrote:Which of the following is equal to 2^k*5^(k-1)?
A. 2*10^(k-1)
B. 5*10^(k-1)
C. 10^k
D. 2*10^k )
E. 10^(2k-1)
The OA is A.
How can I rewrite the given expression to get A? I need your help experts. Please. Thanks in advance.
2^k * 5^(k-1) = 2^1 * 2^(k-1) * 5^(k-1) = 2 * (2*5)^(k-1) = 2 * 10^(k-1)
Answer: A
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