Question

Скільки буде 12/80+9/15-7/8+4/5

Answer 1

$\frac{12}{80} + \frac{9}{15} - \frac{7}{8} + \frac{4}{5}$

Сокращаем 12/80 на ОД 2:

$\frac{6}{40} + \frac{9}{15} - \frac{7}{8} + \frac{4}{5}$

Сокращаем 9/15 на ОД 3:

$\frac{6}{40} + \frac{3}{5} - \frac{7}{8} + \frac{4}{5}$

$\frac{6}{40} + \frac{3 + 4}{5} - \frac{7}{8}$

$\frac{6}{40} + \frac{7}{5} - \frac{7}{8} \\ \frac{6}{40} + \frac{7 \times 8}{5 \times 8} - \frac{7 \times 5}{8 \times 5} \\ \frac{6}{40} + \frac{56}{40} - \frac{35}{40} \\ \frac{6 + 56 - 35}{40} \\ \frac{27}{40}$