x*2.2+2.1*y+2*(20-x-y)=42
0.2x+0.1y=2
2x+y=20
y>2,9>x>2
x*2.2*6+2.1*y*8+2*5*(20-x-y)=w
2x+y=20
13.2x+16.8y+200-10x-10y=w
3.2x+6.8y+200=W
3.2x+6.8*(20-2x)+200=w
336-10.4x=w
x*2.2+2.1*y+2*(20-x-y)=42
0.2x+0.1y=2
2x+y=20
y>2,9>x>2
x*2.2*6+2.1*y*8+2*5*(20-x-y)=w
2x+y=20
13.2x+16.8y+200-10x-10y=w
3.2x+6.8y+200=W
3.2x+6.8*(20-2x)+200=w
336-10.4x=w