(1)2x-3y=5 3x+2y=1 (2)x+2y=3 x-3y+z=0 2x+y-z=5
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(1)2x-3y=5 3x+2y=1 (2)x+2y=3 x-3y+z=0 2x+y-z=5
(1)
2x-3y=5(1)
3x+2y=1 (2)
(2)×2- (1)×3:
13y = 2- 15
13y = -13
y=-1
代入到(1):
2x + 3 = 5
2x =2
x=1
(2)x+2y=3 (1)
x-3y+z=0 (2)
2x+y-z=5(3)
由(1):
x= 3-2y
代入到(2)和(3):
3-2y-3y +z=0
6-4y +y -z =5
整理后:
-5y +z = -3
-3y -z = -1
两式相加:
-8y = -4
y =-1/2
代入到(1):
x= 3 + 1= 4
代入到(2):
4 + 3/2 +z = 0
z = -11/2
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2x-3y=5(1)
3x+2y=1 (2)
(2)×2- (1)×3:
13y = 2- 15
13y = -13
y=-1
代入到(1):
2x + 3 = 5
2x =2
x=1
(2)x+2y=3 (1)
x-3y+z=0 (2)
2x+y-z=5(3)
由(1):
x= 3-2y
代入到(2)和(3):
3-2y-3y +z=0
6-4y +y -z =5
整理后:
-5y +z = -3
-3y -z = -1
两式相加:
-8y = -4
y =-1/2
代入到(1):
x= 3 + 1= 4
代入到(2):
4 + 3/2 +z = 0
z = -11/2
【书情雅致为您答题 ,肯定对】
【有什么不明白可以对该题继续追问】
【如果满意,请及时选为满意答案,
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