Class 9th math 2.4 solution english PCTB

Question 4: Find the value of \(x\) in the following equations:

\((iii)\) \(\quad\) \(( 81)^{x} =( 243)^{x+2} \)

Solution:

\[
\begin{align*}
( 81)^{x} &=( 243)^{x+2}\\
( 3)^{4x} &=( 3)^{5( x+2)}\\
( 3)^{4x} &=( 3)^{5x+10}\\
\end{align*}
\]

Equating bases, we have

\[
\begin{align*}
4x&=5x+10\\
-10&=5x-4x\\
-5&=x
\end{align*}
\]

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