a) 99 \frac{15}{5} = 99 + 3 = 102; 207 \frac{101}{101} = 207 + 1 = 208
б) 8 \frac{17}{4} = 8 + \frac{16}{4} + \frac{1}{4} = 8 + 4 + \frac{1}{4} = 12 \frac{1}{4}; 16 \frac{25}{9} = 16 + \frac{18}{9} + \frac{7}{9} = 16 + 2 + \frac{7}{9} = 18 \frac{7}{9}; 31 \frac{107}{4} = 31 + \frac{104}{4} + \frac{3}{4} = 31 + 26 + \frac{3}{4} = 57 \frac{3}{4}.
Ответ:
a) 102; 208
б) 12 \frac{1}{4}; 18 \frac{7}{9}; 57 \frac{3}{4}