Difference between revisions of "2021 AMC 12B Problems/Problem 3"

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<math>\textbf{(A) }\frac34 \qquad \textbf{(B) }\frac78 \qquad \textbf{(C) }\frac{14}{15} \qquad \textbf{(D) }\frac{37}{38} \qquad \textbf{(E) }\frac{52}{53}</math>
 
<math>\textbf{(A) }\frac34 \qquad \textbf{(B) }\frac78 \qquad \textbf{(C) }\frac{14}{15} \qquad \textbf{(D) }\frac{37}{38} \qquad \textbf{(E) }\frac{52}{53}</math>
  
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==Solution 1==
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Subtracting <math>2</math> from both sides and taking reciprocals gives 1+\frac{1}{2+\frac{2}{3+x}}=\frac{53}{38}<math>. Subtracting </math>1<math> from both sides and taking reciprocals again gives </math>2+\frac{2}{3+x}=\frac{38}{15}<math>. Subtracting </math>2<math> from both sides and taking reciprocals for the final time gives </math>\frac{x+3}{2}=\frac{15}{8}<math> or </math>x=\frac{3}{4} \implies \boxed{\textbf{(A) }$.
  
 
== Video Solution by OmegaLearn (Algebraic Manipulations) ==
 
== Video Solution by OmegaLearn (Algebraic Manipulations) ==

Revision as of 21:48, 11 February 2021

Problem

Suppose\[2+\frac{1}{1+\frac{1}{2+\frac{2}{3+x}}}=\frac{144}{53}.\]What is the value of $x?$

$\textbf{(A) }\frac34 \qquad \textbf{(B) }\frac78 \qquad \textbf{(C) }\frac{14}{15} \qquad \textbf{(D) }\frac{37}{38} \qquad \textbf{(E) }\frac{52}{53}$

Solution 1

Subtracting $2$ from both sides and taking reciprocals gives 1+\frac{1}{2+\frac{2}{3+x}}=\frac{53}{38}$. Subtracting$1$from both sides and taking reciprocals again gives$2+\frac{2}{3+x}=\frac{38}{15}$. Subtracting$2$from both sides and taking reciprocals for the final time gives$\frac{x+3}{2}=\frac{15}{8}$or$x=\frac{3}{4} \implies \boxed{\textbf{(A) }$.

Video Solution by OmegaLearn (Algebraic Manipulations)

https://youtu.be/WskJI8_7Gk0

~ pi_is_3.14

See Also

2021 AMC 12B (ProblemsAnswer KeyResources)
Preceded by
Problem 2
Followed by
Problem 4
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
All AMC 12 Problems and Solutions

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