4x+y-3z=0 (1)x-y+2=0 (2)由(2)得y=x+2代入(1),4x+(x+2)-3z=0得z=x+2/3题目错了,结果字母是化不掉的,如果(2) 式中的数字2是字母z,可以求.4x+y-3z=0 (1)x-y+z=0 (2)(1)+(2),得x=0.4z(1)-(2)×4,得y=1.4zx：y：z=0.4z...