first off, let's convert the mixed fractions to "improper" and then divide,
[tex]\bf \stackrel{mixed}{5\frac{1}{4}}\implies \cfrac{5\cdot 4+1}{4}\implies \stackrel{improper}{\cfrac{21}{4}}
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\stackrel{mixed}{2\frac{2}{7}}\implies \cfrac{2\cdot 7+2}{2}\implies \stackrel{improper}{\cfrac{16}{7}}\\\\
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\cfrac{21}{4}\div \cfrac{16}{7}\implies \cfrac{21}{4}\cdot \cfrac{7}{16}\implies \cfrac{147}{64}\implies 2\frac{19}{64}[/tex]
