Ответ:

1.

[tex]a) \frac{3 \times 5 + 1}{3} = \frac{15 + 1}{3} = 5 \frac{1}{3} \\ b) \frac{12 \times 2 + 11}{12} = \frac{24 + 11}{12} = 2 \frac{11}{12} [/tex]

2.

[tex]a) \frac{3 \times 3 + 1}{3} = \frac{9 + 1}{3} = \frac{10}{3} \\ b) \frac{4 \times 4 + 3}{4} = \frac{16 + 3}{4} = \frac{19}{4} [/tex]