7/48 + 7/36

1) $\frac{7}{48} + \frac{7}{36} = \frac{7 \cdot 3}{144} + \frac{7 \cdot 4}{144} = \frac{21}{144} + \frac{28}{144} = \frac{49}{144}$ 2) $\frac{7}{18} - \frac{7}{24} = \frac{7 \cdot 4}{72} - \frac{7 \cdot 3}{72} = \frac{28}{72} - \frac{21}{72} = \frac{7}{72}$ 3) $\frac{11}{36} - \frac{7}{24} = \frac{11 \cdot 2}{72} - \frac{7 \cdot 3}{72} = \frac{22}{72} - \frac{21}{72} = \frac{1}{72}$ 4) $\frac{5}{6} - \frac{1}{15} = \frac{5 \cdot 5}{30} - \frac{1 \cdot 2}{30} = \frac{25}{30} - \frac{2}{30} = \frac{23}{30}$ 5) $\frac{5}{9} - \frac{5}{12} = \frac{5 \cdot 4}{36} - \frac{5 \cdot 3}{36} = \frac{20}{36} - \frac{15}{36} = \frac{5}{36}$