Question

40 выражения 8/15 (2 1/4а- 7 1/2 b) - 7/30 (4 2/7а - 8 4/7 b)

Answer 1

А)
$\frac{8}{15} \times (2 \frac{1}{4} a - 7 \frac{1}{2} ) = \\ \frac{8}{15} \times \frac{9}{4} a - \frac{8}{15} \times \frac{15}{2} = \\ \frac{6}{5} a - 4 = 1 \frac{1}{5} a - 4$
б)
$- \frac{7}{30} \times (4 \frac{2}{7} a - 8 \frac{4}{7} b) = \\ - \frac{7}{30} \times \frac{30}{7} a + \frac{7}{30} \times \frac{60}{7} b = \\ - a + 2b$