1) is: (4,-1)
I: x>3
II: y<=2*x-5
a: (5,6):
I: 5>3 ?yes
II: 6<=2*5-5
6<=5 ?no
This is not a solution
b: (4,-1):
I: 4>3 ?yes
II: -1<=2*4-5
-1<=3 ?yes
This is a solution
c: (-3,-1):
I: -3>3 ?no
This is not a solution
d: (1,11):
I: 1>3 ?no
This is not a solution
2) is (8,-1):
I: x+y>=5
II: x-2*y>8
a: (6,1):
I: 6+1>=5
7>=5 ?yes
II: 6-2*1>8
4>8 ?no
This is not a solution
b: (8,-1):
I: 8+-1>=5
7>=5 ?yes
II: 8-2*-1>8
10>8 ?yes
This is a solution
c: (6,2):
I: 6+2>=5
8>=5 ?yes
II: 6-2*2>8
2>8 ?no
This is not a solution
d: (6,-2):
I: 6+-2>=5
4>=5 ?no
This is not a solution
3) is (6,2):
I: 2*x+4*y>0
II: -x+5*y>0
a: (0,0):
I: 2*0+4*0>0
0>0 ?no
This is not a solution
b: (-4,-2):
I: 2*-4+4*-2>0
-16>0 ?no
This is not a solution
c: (6,2):
I: 2*6+4*2>0
20>0 ?yes
II: -6+5*2>0
4>0 ?yes
This is a solution
d: (6,0):
I: 2*6+4*0>0
12>0 ?yes
II: -6+5*0>0
-6>0 ?no
This is not a solution