[tex]1 \frac{1}{4} - 1 \frac{2}{7} + \frac{1}{2} \\ [/tex]
[tex] \frac{5}{4} - \frac{9}{7} + \frac{1}{2} = [/tex]
[tex] \frac{5 \times 7}{28} - \frac{9 \times 4}{28} + \frac{14}{28 } = [/tex]
[tex] \frac{35 - 36 + 14}{28} = [/tex]
[tex] \frac{ 13}{28} [/tex]
