Problem

MATH OLYMPIAD
\[
\begin{array}{l}
\left\{\begin{array}{l}
6^{x}+6^{y}=42 \\
x+y=3
\end{array}\right. \\
x=? y=?
\end{array}
\]

Answer

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Answer

Substitute \(x=2\) and \(y=1\) into the original equations, we find this works.

Steps

Step 1 :Let's denote \(6^x=a\) and \(6^y=b\).

Step 2 :Then, the equations become \(a+b=42\) and \(x+y=3\).

Step 3 :From the second equation, we can express \(y\) as \(y=3-x\).

Step 4 :Substitute \(y\) into the first equation, we get \(a+6^{3-x}=42\).

Step 5 :Rearrange the equation, we get \(a=42-6^{3-x}\).

Step 6 :Substitute \(a\) into the second equation, we get \(x+\frac{\log(42-6^{3-x})}{\log(6)}=3\).

Step 7 :Solving this equation, we get \(x=\boxed{2}\) and \(y=\boxed{1}\).

Step 8 :Substitute \(x=2\) and \(y=1\) into the original equations, we find this works.

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