Explicație pas cu pas:
[tex]5 \frac{1}{2} - 3 \frac{1}{4} = \frac{2 \times 5 + 1}{2} - \frac{4 \times 3 + 1}{4} = \frac{11}{2} - \frac{13}{4} = \frac{22 - 13}{4} = \frac{9}{4} [/tex]
[tex]13 \frac{1}{2} - 11 \frac{6}{7} = \frac{2 \times13 + 1 }{2} - \frac{7 \times 11 + 6}{7} = \frac{27}{2} - \frac{83}{7} = \frac{27 \times 7 - 83 \times 2}{14} = \frac{189 - 166}{14} = \frac{23}{14} [/tex]
