7 supra 12-1 supra 8
11 supra 15-7 supra 20
17 supra 12-3 supra 16

[tex] \frac{7}{12} - \frac{1}{8} = \frac{14}{24} - \frac{3}{24} = \frac{14 - 3}{24} = \frac{11}{24} [/tex]

[tex] \frac{11}{15} - \frac{7}{20} = \frac{44}{60} - \frac{21}{60} = \frac{44 - 21}{60} = \frac{23}{60} [/tex]

[tex] \frac{17}{12} - \frac{3}{16} = \frac{68}{48} - \frac{9}{48} = \frac{68 - 9}{48} = \frac{59}{48} [/tex]

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