数学题:11x+3z=8 ; 2x+2y+z=5 ; 2x-6y+4z=-14

问题描述:

数学题:11x+3z=8 ; 2x+2y+z=5 ; 2x-6y+4z=-14

算式2,两边同时乘3。然后与算式3,相加,得出8x+7z=1(算式4)
算式1,两边同时乘3。算式4,两边同时乘7。然后相减,得出x=1,y=2,z=-1

2x+2y+z=5×3 6x+6y+3z=15+2x-6y+4z=-148x+7z=18x+7z=1×324x+21z=311x+3z=8×777x+21z=5677x+21z=56-24x+21z=3 53x=53x=1x=1代入 24x+21z=3 z=-1z=-1代6x+6y+3z=15y=2