Question

4x-y+z=25,6x-z+2y=22,x+3y+z=-2

Answer 1

4x-y+z=25 ①

6x-z+2y=22②

x+3y+z=-2 ③

①+②

10x+y=47 ④

②+③

7x+5y=20 ⑤

④×5-⑤

50x+5y-(7x+5y)=235-20

43x=215

x=5

将x=5代入④

y=47-10x=47-50=-3

将x=5,y=-3代入③

z=-2-x-3y=-2-5+9=2

方程组的解为：x=5,y=-3,z=2.