Решение:
a) $$17 \frac{3}{4} = \frac{17 \cdot 4 + 3}{4} = \frac{68 + 3}{4} = \frac{71}{4} = 17.75$$
б) $$12 : \frac{1}{4} = 12 \cdot 4 = 48$$
в) $$\frac{6}{13} : 3 = \frac{6}{13} \cdot \frac{1}{3} = \frac{2}{13}$$
г) $$8:18 = \frac{8}{18} = \frac{4}{9}$$
д) $$\frac{2}{15} : 1 = \frac{2}{15}$$
e) $$\frac{1}{8} : 1 \frac{11}{24} = \frac{1}{8} : \frac{35}{24} = \frac{1}{8} \cdot \frac{24}{35} = \frac{3}{35}$$
ж) $$3 \frac{3}{9} : 2 \frac{2}{3} = 3 \frac{1}{3} : 2 \frac{2}{3} = \frac{10}{3} : \frac{8}{3} = \frac{10}{3} \cdot \frac{3}{8} = \frac{10}{8} = \frac{5}{4} = 1 \frac{1}{4} = 1.25$$
з) $$12 \frac{6}{7} : 3 = \frac{12 \cdot 7 + 6}{7} : 3 = \frac{84 + 6}{7} : 3 = \frac{90}{7} : 3 = \frac{90}{7} \cdot \frac{1}{3} = \frac{30}{7} = 4 \frac{2}{7}$$
Ответ:
а) 17.75
б) 48
в) 2/13
г) 4/9
д) 2/15
е) 3/35
ж) 1.25
з) 4 2/7