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Solve for x write the exact answer using either base -10 or base-e logarithms

Solve for x write the exact answer using either base -10 or base-e logarithms-example-1
User Chronium
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1 Answer

3 votes

Given:

The given expression is
2^(x+5)=13^(2 x)

We need to determine the value of x using either base - 10 or base - e logarithms.

Value of x:

Let us determine the value of x using the base - e logarithms.

Applying the log rule that if
f(x)=g(x) then
\ln (f(x))=\ln (g(x))

Thus, we get;


\ln \left(2^(x+5)\right)=\ln \left(13^(2 x)\right)

Applying the log rule,
\log _(a)\left(x^(b)\right)=b \cdot \log _(a)(x), we get;


(x+5) \ln (2)=2 x \ln (13)

Expanding, we get;


x \ln (2)+5 \ln (2)=2 x \ln (13)

Subtracting both sides by
5 \ln (2), we get;


x \ln (2)=2 x \ln (13)-5 \ln (2)

Subtracting both sides by
2 x \ln (13), we get;


x \ln (2)-2 x \ln (13)=-5 \ln (2)

Taking out the common term x, we have;


x( \ln (2)-2 \ln (13))=-5 \ln (2)


x=(-5 \ln (2))/(\ln (2)-2 \ln (13))


x=(5 \ln (2))/(2 \ln (13)-\ln (2))

Thus, the value of x is
x=(5 \ln (2))/(2 \ln (13)-\ln (2))

User Will Thomson
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