Answer
$x=\frac{r}{s+t}$, where $s\neq0$ and $t\neq 0$.
Work Step by Step
The given equation is
$\Rightarrow sx+tx=r$
Use distributive property.
$\Rightarrow x(s+t)=r$
Divide each side by $s+t$.
$\Rightarrow \frac{x(s+t)}{s+t}=\frac{r}{s+t}$
Simplify.
$\Rightarrow x=\frac{r}{s+t}$
Hence, the rewritten literal equation is $x=\frac{r}{s+t}$, where $s\neq0$ and $t\neq 0$.
