设x=3a,y=4a, z=7a那么9a+8a-28a=9a=-9/11所以x=-27/11y=-36/11z=-63/11x+y+z=-126/11
设X/3=Y/4=Z/7=ax=3a y=4a z=7a有 9a + 8a -28a=9a= - 9 /11x+y+z =14a= -126/11
