Question

Помогите пожалуйста -40×(-7×+5)=-1600​

Answer 1

$- 40 \times ( - 7x + 5) = - 1600 \\ 280x + ( - 200) = - 1600 \\ 280x = - 1600 + 200 \\ 280x = - 1400 \\ x = - 1400 \div 280 \\ x = - 5$