# How do you solve for x in rx=8=e?

Jul 26, 2016

Is this question correct?

#### Explanation:

$e$ is normally used as a reserved constant and is of value

$2.71818 \ldots .$ It is one of the 'Irrational numbers'

So as the constant $e = 2.71818 . .$ it is not correct to write $8 = e$

$e$ is so important that it is even used as a logarithmic base normally written as 'ln'

So in the same way you could have log(10) you can have ln(10)

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$\textcolor{red}{\text{Assumption: The question is wrong}}$

Suppose the question should read as:$\textcolor{b r o w n}{\text{ } r x = 8}$

Then divide both sides by $\textcolor{b l u e}{r}$ giving:

$\text{ } \textcolor{b r o w n}{\frac{r}{\textcolor{b l u e}{r}} \times x = \frac{8}{\textcolor{b l u e}{r}}}$

But $\frac{r}{r} = 1$ giving:

$\text{ } x = \frac{8}{r}$