Question

Знайди добуток
1) 3/7*1 2/5
2) 2 11/12*1 1/5

Answer 1

1)

$\frac{3}{7} \times 1 \frac{2}{5} = \frac{3}{7} \times \frac{2 + 1 \times 5}{5} = \frac{3}{7} \times \frac{7}{5} = \frac{3 \times 7}{7 \times 5} = \frac{21}{35} = \frac{3 \times 7}{5 \times 7} = \frac{3}{5}$

2)

$2 \frac{11}{12} \times 1 \frac{1}{5} = \frac{11 + 2 \times 12}{12} \times \frac{1 + 1 \times 5}{5} = \frac{35}{12} \times \frac{6}{5} = \frac{35 \times 6}{12 \times 5} = \frac{210}{60} = \frac{7 \times 30}{2 \times 30} = \frac{7}{2} = \frac{3 \times 2 + 1}{2} = 3 \frac{1}{2}$