1.2x+3y+4z=8 and 3x+9y+12z=7
2.2x+3y+4z=2 and 4x+6y+8z=9
3.3x+2y+4z=0 and 3x+4y+2z=0
4. 2x+4y+8z=9 and 4x+2y+7z=0
Answer:2