Question

Найдите корни уравнений




распишите подробно​

Answer 1

Пошаговое объяснение:

1)

$\frac{2}{5} - \frac{3}{5} x = \frac{2}{5 } - \frac{1}{10} x + 3 \\ - \frac{3}{5} x = - \frac{1}{10} x + 3$

умножаем обе части равенства на 10:

$- 6x = - x + 30 \\ - 5x = 30 \\ x = - 6 \\$

2)

$\frac{5}{6} m + 2 = \frac{1}{3} m - 0.8 \\ \frac{5}{6} m - \frac{1}{3} m = - 0.8 - 2 \\ \frac{5m - 2m}{6} = - 2.8 \\ \frac{3m}{6} = - 2.8 \\ \frac{m}{2} = - 2.8 \\$

$m = - 5.6$

3)

$\frac{3}{4} y - 12 = 5 - \frac{1}{4} - 12 \\ \frac{3}{4} y = 5 - \frac{1}{4} \\ \frac{3}{4} y = \frac{20 - 1}{4} \\ \frac{3}{4} y = \frac{19}{4} \\ y = \frac{19}{4} \div \frac{3}{4} \\ y = \frac{19 \times 4}{ 4\times 3} \\$

$y = \frac{19}{3}$

4)

$\frac{7}{12} n - 3 = \frac{1}{2} n + 0.7 \\ \frac{7}{12} n - \frac{1}{2} n = 3.7 \\ n( \frac{7}{12} - \frac{1}{2} ) = 3.7 \\ n \frac{7 - 6}{12} = 3.7 \\ \frac{n}{12} = 3.7 \\$

$n = 12 \times 3.7$

$n = 44.4$