Question

решите уравнение 1/5x+7=21−1/20x

Answer 1

Ответ:

$\frac{1}{5} x + 7 - 21 + \frac{1}{20} x = 0 \\ \frac{1}{5} + \frac{1}{20} = \frac{4}{20} + \frac{1}{20} = \frac{5}{20} = \frac{1}{4}$

$\frac{1}{4} x - 14 = 0 \\ \frac{1}{4} x =0 + 14$

$\frac{1}{4} x = 14 \\ x = 14 \div \frac{1}{4} = 14 \times 4 \\ x = 56$