Combine the numerator into an improper fraction:

\(\displaystyle{8}{\frac{{{3}}}{{{4}}}}+{3}{\frac{{{2}}}{{{3}}}}={8}+{3}+{\frac{{{3}}}{{{4}}}}+{\frac{{{2}}}{{{3}}}}\)

\(\displaystyle={\frac{{{132}}}{{{12}}}}+{\frac{{{9}}}{{{12}}}}+{\frac{{{8}}}{{{12}}}}\)

\(\displaystyle={\frac{{{149}}}{{{12}}}}\)

Do the same for the denominator:

\(\displaystyle{4}+{\frac{{{2}}}{{{5}}}}-{1}{\frac{{{7}}}{{{8}}}}={4}-{1}+{\frac{{{2}}}{{{5}}}}-{\frac{{{7}}}{{{8}}}}\)

\(\displaystyle={\frac{{{120}}}{{{30}}}}+{\frac{{{16}}}{{{40}}}}-{\frac{{{35}}}{{{40}}}}\)

\(\displaystyle={\frac{{{101}}}{{{40}}}}\)

Then divide both:

\(\displaystyle{\frac{{{\frac{{{149}}}{{{12}}}}}}{{{\frac{{{101}}}{{{40}}}}}}}={\frac{{{149}}}{{{101}}}}\cdot{\frac{{{40}}}{{{12}}}}\)

\(\displaystyle={\frac{{{149}}}{{{101}}}}\cdot{\frac{{{10}}}{{{3}}}}\)

\(\displaystyle{\frac{{{1490}}}{{{303}}}}\)

\(\displaystyle={4}+{\frac{{{278}}}{{{303}}}}\)

\(\displaystyle{8}{\frac{{{3}}}{{{4}}}}+{3}{\frac{{{2}}}{{{3}}}}={8}+{3}+{\frac{{{3}}}{{{4}}}}+{\frac{{{2}}}{{{3}}}}\)

\(\displaystyle={\frac{{{132}}}{{{12}}}}+{\frac{{{9}}}{{{12}}}}+{\frac{{{8}}}{{{12}}}}\)

\(\displaystyle={\frac{{{149}}}{{{12}}}}\)

Do the same for the denominator:

\(\displaystyle{4}+{\frac{{{2}}}{{{5}}}}-{1}{\frac{{{7}}}{{{8}}}}={4}-{1}+{\frac{{{2}}}{{{5}}}}-{\frac{{{7}}}{{{8}}}}\)

\(\displaystyle={\frac{{{120}}}{{{30}}}}+{\frac{{{16}}}{{{40}}}}-{\frac{{{35}}}{{{40}}}}\)

\(\displaystyle={\frac{{{101}}}{{{40}}}}\)

Then divide both:

\(\displaystyle{\frac{{{\frac{{{149}}}{{{12}}}}}}{{{\frac{{{101}}}{{{40}}}}}}}={\frac{{{149}}}{{{101}}}}\cdot{\frac{{{40}}}{{{12}}}}\)

\(\displaystyle={\frac{{{149}}}{{{101}}}}\cdot{\frac{{{10}}}{{{3}}}}\)

\(\displaystyle{\frac{{{1490}}}{{{303}}}}\)

\(\displaystyle={4}+{\frac{{{278}}}{{{303}}}}\)