{x+y+z=6,x-z=2,2x-y+z=5 解方程组

网友回答

x+y+z=6 (1)
x-z=2 (2)
2x-y+z=5 (3)
(1)+(3)
3x+2z=11 (4)
(2)×2+(2)
2x+3x=4+11
5x=15所以x=3z=x-2=1
y=6-x-z=2
======以下答案可供参考======
供参考答案1:
x=3y=2z=1供参考答案2:
{x+y+z=6, ①
{x-z=2, ②
{2x-y+z=5 ③
①+③得3x+2z=11 ④
②×2+④得5x=15
x=3把x=3代入②得3-z=2
z=1把x=3、z=1代入①得3+y+1=6
y=2所以原方程组的解是
{x=3{y=2{z=1