Question

Упростить: -0,8y*7x

Раскрыть скобки: 4-(5x+9y-7)-6(-a-3b+4c

Вычислить: 4,2*(-7)-9,3:(5,8-8,9)

Answer 1

$- 0.8y \times 7x = - 5.6xy \\ 4 - 5x - 9y + 7 - 6a + 18b - 24c = \\ 11 - 5x - 9y - 6a + 18b - 24c$

$4.2 \times ( - 7) - 9.3 \div (5.8 - 8.9) = \\ = - 26.4$

$1)4.2 \times ( - 7) = - 29.4 \\ 2)5.8 - 8.9 = - 3.1 \\ 3)9.3 \div ( - 3.1) = - 3$

$4) - 29.4 - ( - 3) = - 29.4 + 3 = \\ - 26.4$