Question

Решите уравнение 75-960:(x+39)=55

Answer 1

$75 - 960 \div (x + 39) = 55 \\ 75 - \frac{960}{x + 39} = 55 \\ - \frac{960}{x + 39} = 55 - 75 \\ - \frac{960}{x + 39} = - 20 \\ 960 = (x + 39) \times 20 \\ 960 = 20x + 780 \\ 960 - 20x = 780 \\ - 20x = 780 - 960 \\ - 20x = - 180 \\ x = 9$