Question

Помогите пожалуйста срочно​

Answer 1

Решаем "крестом"

1) $\frac{2x + 1}{8,1} = \frac{2}{1,8}$

$2x + 1 = \frac{2 * 8,1}{1, 8} = \frac{16,2}{1,8}= 9$

$2x + 1 =9\\2x = 8\\x = 4$

2) $\frac{3x - 1}{3,5} = \frac{2,8}{0,7}$

$3x -1 = \frac{3,5 * 2,8}{0,7} = \frac{9,8}{0,7} = 14$

$3x - 1 = 14\\3x = 15\\x = 5$

3) $\frac{1,4}{2x - 1} = \frac{2,1}{7,5}$

$2x - 1 = \frac{1,4 * 7,5}{2,1} = \frac{10,5}{2,1} = 5$

$2x - 1 = 5\\2x = 6\\x = 3$