1) 3x+2y+z-2x-2y-z=55-40; x+y=15; x=15-y.
2) 30+y+z=40 y+z=10
45-y+z=55; y-z= -10 y=0.
3) 2x+z=40
3x+z=50; x=15
z=10;
y=0
1) 3x+2y+z-2x-2y-z=55-40; x+y=15; x=15-y.
2) 30+y+z=40 y+z=10
45-y+z=55; y-z= -10 y=0.
3) 2x+z=40
3x+z=50; x=15
z=10;
y=0