well, the longer piece is clearly the latter, so let's firstly convert the mixed fractions to improper fractions and then subtract.
[tex]\stackrel{mixed}{14\frac{3}{8}}\implies \cfrac{14\cdot 8+3}{8}\implies \stackrel{improper}{\cfrac{115}{8}} ~\hfill \stackrel{mixed}{25\frac{1}{16}}\implies \cfrac{25\cdot 16+1}{16}\implies \stackrel{improper}{\cfrac{401}{16}} \\\\[-0.35em] ~\dotfill\\\\ \cfrac{401}{16}~~ - ~~\cfrac{115}{8}\implies \implies \cfrac{(1)401~~ - ~~(2)115}{\underset{\textit{using this LCD}}{16}}\implies \cfrac{171}{16}\implies 10\frac{11}{16}[/tex]
