Answer:
[tex]D.\ 7 \frac{3}{4} * \frac{\sqrt{16} }{5} = \frac{31}{4} * \frac{4}{5} = \frac{31}{5} \\\\C. \ 7 \frac{3}{4} + \frac{\sqrt{16} }{5} =\frac{31}{4} + \frac{4}{5} = \frac{171}{20}[/tex]