{5x+2y-2z=6,3x-2y+z=7,x+y-z=0

题目

{5x+2y-2z=6,3x-2y+z=7,x+y-z=0

答案

{5x+2y-2z=6 (1){3x-2y+z=7 (2){x+y-z=0 (3)(1)+(2)可得：8x-z=13 (4)(3)×2得：2x+2y-2z=0 (5)(2)+(5)可得：5x-z=7 (6)(4)-(6)得：3x=6解得：x=2,代入(6)得：10-z=7解得：z=3将x=2,z=3代入(3)得：2...