a) $\frac{2727}{4242}$= $\frac{2727:303}{4242:303}$ =$\frac{9}{14}$
b) $\frac{120120}{-240240}$ = $\frac{120120:120120}{-240240:120120}$ = $\frac{1}{-2}$ = $\frac{-1}{2}$
c) $\frac{1515}{-1717}$ = $\frac{1515:(-101)}{-1717:(-101)}$ = $\frac{-15}{17}$
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