Объяснение:

1)

y = 2+x

y+y+x = 4+2x+x = 28

3x = 24

x = 8

y = 2+x = 10

2)

y = 2+x

2x+3y = 2x+6+3x = 29

5x = 23

x = 5.6

y = 2+x = 7.6