1/4 х - у/3 больше либо равно 1/3-у

5y+9<=3-7y

5y+7y<=3-9

12y<=-6

y<=-6/12

y<=-1/2

3x+1<=4x-5

3x-4x<=-5-1

-x<=-6

x<=6

1/4-y/3>=1/3-y

y-y/3>=1/3-1/4

(3y-y) / 3> = (4-3) / 12

2y/3>=1/12

2y>=3/12

2y>=1/4

y>=1/8

6y>3y-2

6y-3y>-2

3y>-2

y>-2/3

3-7y>5y-3

3+3>5y+7y

6>12y

y<6/12

y<1/2

x/6+1/2>x-1/3

1/2+1/3>x-x/6

(3+2) / 6> (6x-x) / 6

5/6>5x/6

x<5/6*6/5

x<0