let's firstly convert the mixed fractions to improper fractions and then get their difference.
[tex]\stackrel{mixed}{5\frac{3}{4}}\implies \cfrac{5\cdot 4+3}{4}\implies \stackrel{improper}{\cfrac{23}{4}} ~\hfill \stackrel{mixed}{1\frac{5}{8}}\implies \cfrac{1\cdot 8+5}{8}\implies \stackrel{improper}{\cfrac{13}{8}} \\\\[-0.35em] ~\dotfill\\\\ \stackrel{\textit{Saturday and Sunday}}{\cfrac{23}{4}}~~ - ~~\stackrel{Saturday~only}{\cfrac{13}{8}}\implies \cfrac{(2)23~~ - ~~(1)13}{\underset{\textit{using this LCD}}{8}}\implies \underset{Sunday~only}{\cfrac{33}{8}\implies 4\frac{1}{8}}[/tex]
