[tex]6 \frac{7}{8}.[/tex]
The easiest way to solve this problem is to sum the whole number and the fractions separately.
[tex]4\frac{5}{8} + 2\frac{1}{4}\\\\4\frac{5}{8} + 2 \frac{1}{4}(\frac{2}{2})\\\\4\frac{5}{8} + 2\frac{2}{8}[/tex]
Solving the sum:
[tex]4\frac{5}{8} + 2\frac{2}{8} = 6 \frac{7}{8}[/tex]
