x + y > 23
y = 3x - 5
24 is the smallest integer greater than 23
so use x + y = 24
Rearrange
y= 24 - x
Now substitute into the other equation
24 - x = 3x - 5
Solve
29 = 4x
x=7.25 -> not an integer, round down since you want the least value
x=7
y= 3(7) - 5
y= 16