Question

помогите пожалуйста!!

Answer 1

Ответ:

$1) \frac{21 - x}{6} = \frac{7}{4} \\ 84 - 4x = 42 \\ 4x = 42 \\ x = 10.5 \\ \\ 2)8 = \frac{13}{x} \\x = \frac{13}{8} \\ x = 1 \frac{5}{8} \\ x = 1.625$

$3) \frac{2}{3} \div x = 3 \div 2 \frac{1}{7} \\ \frac{2}{3} \div x = \frac{3 \times 7}{15} \\ \frac{2}{3} \div x = \frac{7}{5} \\ x = \frac{2}{3} \div \frac{7}{5} \\ x = \frac{10}{21}$