Question

(5/7 - 2/3*у )*21 = 1
Надо найти "у", помогите :(

Answer 1

(5/7 - 2/3 • у) • 21 = 1
21•5/7 - 21•2у/3 = 1
3•5 - 7•2у = 1
15 - 14у = 1
-14у = -15+1
-14у = -14
у = -14 : (-14)
у = 1

Answer 2

5/7-2/3×y=1/21
2/3×y=5/7-1/21
2/3×y=14/21
2/3×y=2/3
y=1