Which table represents a linear function?

х

X

1

у

1

х

1

y

7

1

y

1

2

1

1

2

2

2

3

4

9

13

21

3

1ż

1

2

1

3

1

4

3

4

2

O

4

Х

1

у

0

2

3

4.

6

16

30