Question

2/3-(x-1/21)=2/7 пжжжж быстро

Answer 1

$\frac{2}{3} - (x - \frac{1}{21} ) = \frac{2}{7} \\ x - \frac{1}{21} = \frac{2}{3} - \frac{2}{7} \\ x - \frac{1}{21} = \frac{14}{21} - \frac{6}{21} \\ x - \frac{1}{21} = \frac{8}{21} \\ x = \frac{8}{21} + \frac{1}{21} \\ x = \frac{9}{21} \\ x = \frac{3}{7}$