Question

2) 21/50 * у = 1; 4) 29/38 * у = 1

Answer 1

21/50*у=1
0,42*у=1
у=2,38095238
21/50*2,38095238=1
29/38*у=1
0,76315789*у=1
у=1,31034484
29/38*1,31034484=1

Answer 2

у=38/29

Answer 3

29/38*38/29=1

Answer 4

так вы пишите?