x+y+z=11 100z+10y+x-100x+10y+z=693 100x+10z+y-100x+10y+z=54解方程组

x+y+z=11 (1)100z+10y+x-100x+10y+z=693 (2)100x+10z+y-100x+10y+z=54 (3)(3) => 11y+11z=54 ≡ (3)(1)*99+(2),=> 119y+200z=1782 (4)(3)*200-(4)*11,=>(11*200-119*11)y=54*200-1782*11891y=-8802,=>y=-8802/891=-9...