[tex]a) \frac{4}{21} + \frac{24}{21} = \frac{4 + 24}{21} = { \frac{28}{21} }^{(7} = \frac{4}{3} = 1 \frac{1}{3} [/tex]
[tex]b) \frac{47}{14} - \frac{19}{14} = \frac{47 - 19}{14} = \frac{28}{14} = 2 [/tex]
[tex]c) \frac{7}{2} + \frac{6}{4} = \frac{7 \times 2}{2 \times 2} + \frac{6}{4} = \frac{14}{4} + \frac{6}{4} = \frac{14 + 6}{4} = \frac{20}{4} = 5 [/tex]
