[tex] 1) \frac{13}{3}- \frac{7}{3}=2; 2) \frac{37}{36}- \frac{1}{6}= \frac{1}{36}; 3) \frac{1}{5}- \frac{1}{7}= \frac{2}{35};4) 3- \frac{2}{5}= \frac{13}{15}; 5) 7- \frac{3}{8}= \frac{53}{8}; 6) \frac{9}{2}- \frac{3}{6}= \frac{5}{2} [/tex]
7) 17 supra 27 - 11 supra 27=16 supra 27
