2x-1 <= 4

2x <= 5

x<=5/2 so x is 2 or 1.

2x+2y <= 7(use x=1)

2 + 2y <= 7

2y <= 5

y <= 5/2 so y = 2 or 1.

2x+2y <= 7 (use x=2)

4 + 2y <= 7

2y <= 3

y <= 3/2 so y = 1

Sometimes 0 is considered a natural number. In that case, any of the above could include 0 for y. And if x = 0:

2y <= 7

y <= 7/2 so y could be 3, 2, 1 or 0