Consider the following algebraic equation:
[tex]sx\text{ + tx = r}[/tex]Applying a common factor on the left side of the equation, we get:
[tex]x(s+t)=r[/tex]finally, solving for x, we obtain:
[tex]x\text{ =}\frac{r}{s+t}[/tex]we can conclude that the correct answer is:
Answer:[tex]x\text{ =}\frac{r}{s+t}[/tex]