3x+2y-z=1,2x-y+2z=5,5x-2y+3z=13

问题描述:

3x+2y-z=1,2x-y+2z=5,5x-2y+3z=13

3x+2y-z=1 ①2x-y+2z=5 ②5x-2y+3z=13 ③由③+①得:8x+2z=14 即4x+z=7 ④由①+②×2得:7x+3z=11 ⑤由④×3-⑤得:5x=10x=2把x=2代入④得:8+z=7z=-1把x=2,z=-1代入②得:4-y-2=5y=-3所以方程组的解为:x=2 y=-3 z=...