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Answer :

Answer:

x = 1.3863

Explanation:

We can rewrite our equation as

[tex](e^x)^2-e^x-12=0[/tex]

which can be factored as

[tex](e^x+3)(e^x-4)=0[/tex]

Therefore, the two equations we must solve are

[tex]\begin{gathered} e^x+3=0 \\ e^x-4=0 \end{gathered}[/tex]

The first equation gives

[tex]\begin{gathered} e^x+3=0 \\ \Rightarrow e^x=-3 \end{gathered}[/tex]

Since the natural logarithm can never give a negative number, the above equation is undefined.

Now the second equation gives

[tex]e^x-4=0[/tex][tex]e^x=4[/tex]

taking the natural log of both sides gives

[tex]\ln[e^x]=\ln[4][/tex][tex]\boxed{x=\ln[4].}[/tex]

which we evaluate to get (rounded to the nearest four decimal places)

[tex]\boxed{x=1.3862.}[/tex]

which is our answer!