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Find x, if (1/3)^-4 x (1/3)^-8 = (1/3)^-2x

User Takirala
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1 Answer

19 votes
19 votes


{ \overline{ \qquad \qquad \qquad \qquad \qquad \qquad \qquad \qquad \qquad}}


\large \underline \mathbb{PROBLEM : }


\qquad\quad\tt{Solve \: for \: x} : \\ \\\qquad\quad \sf \: \bigg( (1)/(3)\bigg)^( - 4) * \bigg( (1)/(3)\bigg)^( - 8) = \bigg( (1)/(3)\bigg)^( - 2x) \\ \\ \\


{ \overline{ \qquad \qquad \qquad \qquad \qquad \qquad \qquad \qquad \qquad}}


\large \underline \mathbb{ANSWER : }


\qquad \qquad \quad\qquad \huge \tt{x = 6 }\\ \\


{ \overline{ \qquad \qquad \qquad \qquad \qquad \qquad \qquad \qquad \qquad}}


\large \underline \mathbb{SOLUTION : }

Given :-


\qquad\quad\large\sf \: \bigg( (1)/(3)\bigg)^( - 4) * \bigg( (1)/(3)\bigg)^( - 8) = \bigg( (1)/(3)\bigg)^( - 2x) \\ \\

We know :-


\qquad \qquad\large\boxed{ \sf{ \: {a}^(x) * {a}^(y) = {a}^(x + y) \: }} \\ \\

We get :-


\large\sf \Longrightarrow \qquad \bigg( (1)/(3)\bigg)^( - 4 + ( - 8)) = \bigg( (1)/(3)\bigg)^( - 2x) \\ \\


\large\sf \Longrightarrow \qquad \bigg( (1)/(3)\bigg)^( - 4 - 8) = \bigg( (1)/(3)\bigg)^( - 2x) \\ \\


\large\sf \Longrightarrow \qquad \bigg( (1)/(3)\bigg)^( - 12) = \bigg( (1)/(3)\bigg)^( - 2x) \\ \\

We know :-


\large \qquad \qquad\boxed{ \sf{ \: {a}^(x) = {a}^(y) \: \sf \: \implies \: x = y \: }} \\ \\

So,


\large\sf\Longrightarrow \quad - 12 = - 2x \\ \\


\large\sf\Longrightarrow \quad \underline{\sf {\red{x = 6}}} \: \sf{ --- \: Final \: Answer} \\ \\


\underline{\rule{190pt}{8pt}} \\

ᜎᜒ
\large \mathfrak{TheFletchhhh \: \: X'D}

User Shane Goodman
by
3.4k points
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