Perform the Indicated Operations $\frac{3}{\mathrm{r}}+\frac{5}{\mathrm{r}+7}$ A) $\frac{8 \mathrm{r}+21}{\mathrm{r}(\mathrm{r}+7)}$ B) $\frac{8 r+21}{r(-7-r)}$ C) $\frac{-21 r-8}{r(-7-r)}$

Multiple Choice

Perform the indicated operations. Give the answer in lowest terms.
- $\frac{3}{\mathrm{r}}+\frac{5}{\mathrm{r}+7}$

A) $\frac{8 \mathrm{r}+21}{\mathrm{r}(\mathrm{r}+7) }$
B) $\frac{8 r+21}{r(-7-r) }$
C) $\frac{-21 r-8}{r(-7-r) }$
D) $\frac{-21 r-8}{\mathrm{r}(\mathrm{r}+7) }$