Question

Решите уравнение.
(5/7 - 2/3 y) * 21 = 1.

Answer 1

(5/7 - 2/3 y) * 21 = 1
5/7 - 2/3y = 1/21
2/3y = 5/7 - 1/21
2/3y = -14/21
y = -14/21  / 2/3
y = 7/7 = 1
Ответ. 1

Answer 2

Спасибо.

Answer 3

$( frac{5}{7} - frac{2}{3} y)*21=1 \ frac{5}{7} - frac{2}{3} y= frac{1}{21} \ frac{2}{3} y=frac{5}{7}-frac{1}{21} \ frac{2}{3} y= frac{5*3-1}{21} \ frac{2}{3} y= frac{14}{21} \ y= frac{14*3}{21*2} \ y=1$

Ответ: у=1