Difference between revisions of "2016 AMC 10B Problems/Problem 1"

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==Video Solution==
 
==Video Solution==
 
https://youtu.be/1IZ3oj1iGf0
 
https://youtu.be/1IZ3oj1iGf0
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~savannahsolver
 
~savannahsolver
  

Revision as of 16:57, 16 June 2020

Problem

What is the value of $\frac{2a^{-1}+\frac{a^{-1}}{2}}{a}$ when $a= \tfrac{1}{2}$?

$\textbf{(A)}\ 1\qquad\textbf{(B)}\ 2\qquad\textbf{(C)}\ \frac{5}{2}\qquad\textbf{(D)}\ 10\qquad\textbf{(E)}\ 20$

Solution

Factorizing the numerator, $\frac{\frac{1}{a}\cdot(2+\frac{1}{2})}{a}$ then becomes $\frac{\frac{5}{2}}{a^{2}}$ which is equal to $\frac{5}{2}\cdot 2^2$ which is $\boxed{\textbf{(D) }10}$.

Video Solution

https://youtu.be/1IZ3oj1iGf0

~savannahsolver

See Also

2016 AMC 10B (ProblemsAnswer KeyResources)
Preceded by
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Followed by
Problem 2
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All AMC 10 Problems and Solutions

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