题目

7.｛4x+3y-2z=-7 ① 8.｛5x-3y+6z=-3 ①
{5x-6y+z=1 ② {3x-y+3z=0 ②
{2x+z=-2 ③ {y+3z=6 ③
x=-1,y=-1,z=0 x=-3,y=0,z=2

提问时间：2021-03-31

答案

4x+3y-2z=-7 (1)
5x-6y+z=1 (2)
2x+z=-2 (3)
(1)×2+(2)
13x-3z=-13 (4)
(3)×3+(4)
19x=-19
x=-1
z=-2-2x=0
y=(-7-4x+2z)/3=-1
5x-3y+6z=-3 (1)
3x-y+3z=0 (2)
y+3z=6 (3)
(2)+(3)
3x+6z=6
x+2z=2 (4)
(2)×3-(1)
4x+3z=3 (5)
(4)×4-(5)
8z-3z=8-3
5z=5
z=1
x=2-2z=0
y=6-3z=3
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