Question

Срочно помогите дам 50 баллов!​

Answer 1

a)

$- 2.86 \times \frac{6}{7} - \frac{6}{7} \times 0.64 = \frac{6}{7} \times ( - 2.86 - 0.64) = \\ \frac{6}{7} \times 3.5 = \frac{6}{7} \times \frac{7}{2} = 3$

б)

$637 \times 36 - 165 \times 36 + 36 \times 28 = \\ 36(637 - 165+ 28) = 36(665 - 165) = \\ 36 \times 500 = 18000$

в)

$78 \times 62 + 13 \times 78 - 75 \times 68 = \\ 78(62 + 13) - 75 \times 68 = \\ 78 \times 75 - 75 + 68 = \\ 75(78 - 68) = 75 \times 10 = 750$