first off, we'd convert the mixed fractions to an "improper" one, and then get the LCD and add them up, recall PEMDAS, parentheses first though,
[tex]\bf \stackrel{mixed}{10\frac{1}{8}}\implies \cfrac{10\cdot 8+1}{8}\implies \stackrel{improper}{\cfrac{81}{8}}
\\\\\\
\stackrel{mixed}{3\frac{5}{8}}\implies \cfrac{3\cdot 8+5}{8}\implies \stackrel{improper}{\cfrac{29}{8}}
\\\\\\
\stackrel{mixed}{2\frac{7}{8}}\implies \cfrac{2\cdot 8+7}{8}\implies \stackrel{improper}{\cfrac{23}{8}}\\\\
-------------------------------[/tex]
[tex]\bf \cfrac{81}{8}+\left( \cfrac{29}{8}+\cfrac{23}{8} \right)\impliedby
\begin{array}{llll}
\textit{LCD for the }\\
\textit{parentheses is 8}
\end{array}\implies \cfrac{81}{8}+\left( \cfrac{29+23}{8} \right)
\\\\\\
\cfrac{81}{8}+\left( \cfrac{52}{8} \right)\implies \cfrac{81}{8}+\cfrac{52}{8}\impliedby \stackrel{LCD}{8}\implies \cfrac{81+52}{8}
\\\\\\
\cfrac{133}{8}\implies 16\frac{5}{8}[/tex]
