[tex]5 \frac{1}{4} - 1 \frac{19}{24} = \frac{5 \times 4 + 1}{4} - \frac{1 \times 24 + 19}{24} = \frac{21}{4} - \frac{43}{24} = \frac{126}{24} - \frac{43}{24} = \frac{83}{24} [/tex]
[tex]37 \frac{3}{5} - 1 \frac{13}{18} = \frac{37 \times 5 + 3}{5} - \frac{1 \times 18 + 13}{18} = \frac{185 + 3}{5} - \frac{31}{18} = \frac{188}{5} - \frac{31}{18} = \frac{3384}{90} - \frac{155}{90} = \frac{3229}{90} [/tex]
[tex]3 \frac{11}{90} - 1 \frac{13}{18} = \frac{3 \times 90 + 11}{90} - \frac{1 \times 18 + 13}{18} = \frac{270 + 11}{90} - \frac{31}{18} = \frac{281}{90} - \frac{31}{18} = \frac{281}{90} - \frac{155}{90} = \frac{126}{90} = \frac{63}{45} = \frac{21}{15} = \frac{7}{5} [/tex]
[tex]67 \frac{61}{88} - 49 \frac{43}{55} = \frac{67 \times 88 + 61}{88} - \frac{49 \times 55 + 43}{55} = \frac{5896 + 61}{88} - \frac{2695 + 43}{55} = \frac{5957}{88} - \frac{2738}{55} = \frac{29785}{440} - \frac{150590}{440} = - \frac{120205}{440} = - \frac{24161}{88} [/tex]
