Answer:
Step-by-step explanation:
[tex]( \frac{r}{3} )(3) \\\frac{r}{3} \times 3[/tex]
Convert elements to fraction :
[tex]3 = \frac{3}{1} [/tex]
[tex] \frac{r}{3} \times \frac{3}{1} = \frac{3r}{3} [/tex]
Cross-cancel common factor :3
[tex] =\frac{r}{1} \\ = r[/tex]