let's firstly convert the mixed fractions to improper fractions, and then add them up.
[tex]\bf \stackrel{mixed}{8\frac{1}{2}}\implies \cfrac{8\cdot 2+1}{2}\implies \stackrel{improper}{\cfrac{17}{2}}~\hfill \stackrel{mixed}{7\frac{2}{3}}\implies \cfrac{7\cdot 3+2}{3}\implies \stackrel{improper}{\cfrac{23}{3}} \\\\[-0.35em] ~\dotfill\\\\ \cfrac{17}{2}+\cfrac{23}{3}\implies \stackrel{\textit{using the LCD of 6}}{\cfrac{(3)17~~+~~(2)23}{6}}\implies \cfrac{51+46}{6}\implies \cfrac{97}{6}\implies 16\frac{1}{6}[/tex]
