.
:
1) 2- .
2) ( ) .
3) .
, (.. ).
:
:
2y + z = 0 (- 2) (- 3)
2x +y 2z = - 2 +
3x + y + z = 8 +
2- 1- , (- 2), 3- 1- , (- 3). :
x 2y + z = 0
5y 4z = -2 (- 7)
7y 2z = 8 5 +
2- 3- .
y 3- , 2- . 3- 2- , (- 7) 3- , 5. :
- 2y + z = 0
5y 4z = -2
18z = 74
z , y 2- (.. z), , , 1- ( y z).
= 2y z = 4 3 = 1
y = 1/5 (4z 2) = 1/5 (12 2) = 2
z = 3
, .
, : z 1 2- , y 1- :
2y + z = 0 x 2y + z = 0 x 2y = -3 5
5y 4z = -2 ó 5y 4z = -2 + ó 5y = 10 2 +
18z = 74: 18 z = 3 4 (- 1) + z = 3
5x = 5: 5 x = 1
ó 5y = 10: 5 ó y = 2
z = 3 z = 3
. , .. ( , ). :
2y + z = 0 (- 2) (- 3) x 2y + z = 0
2x + y 2z = -2 + ó 5y 4z = -2: 5 ó
3x + y + z = 8 + 7y 2z = 8
x 2y + z = 0 x 2y + z = 0 x 2y + z = 0
y 4/5z = -2/5 (- 7) ó y 4/5z = -2/5 ó y 4/5z = -2/5
7y 2z = 8 + 18/5z = 54/5: 18/5 z = 3
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|
. . , .
.
: 2 + y z = 0 x + 2y + z = 3 (- 2) (- 1)
x + 2y + z = 3 ó 2x + y z = 0 + ó
x y 2z = -3 x y 2z = -3 +
x + 2y + z = 3 x + 2y + z = 3 x + 2y + z = 3
- 3y 3z = -6: (- 3) ó y + z = 2 (- 1) ó y + z = 2
- 3y 3z = -6: (- 3) y + z = 2 + 0 = 0
, :
x + 2y + z = 3
ó y + z = 2
z . . y z.
x = 3 2y z = 3 2(2 z) z = - 1
y = 2 z
z = z -
:
x = -1 4
y = 2 c
z = c,
. , , .
.
, .
. . .
:
1) 2- .
2) ( ) .
3) .
, :
2y + z = 0
2x + y 2z = -2
3x + y + z = 8
:
1 -2 1 0 (- 2) (- 3) 1 -2 1 0 1 -2 1 0
= 2 1 -2 -2 + ó 0 5 -4 -2 (- 7) ó 0 5 -4 -2
3 1 1 8 + 0 7 -2 8 5 + 0 0 18 74
, z, y, x. .
:
1 -2 1 0 1 -2 1 0 + 1 -2 0 - 3 5 +
ó 0 5 -4 -2 ó 0 5 -4 - 2 + ó 0 5 0 10 2 ó
0 0 18 74: 18 0 0 1 3 4 (- 1) 0 0 1 3
5 0 0 5: 5 1 0 0 1
0 5 0 10: 5 ó 0 1 0 2
0 0 1 3 0 0 1 3
:
= 1
y = 2
z = 3
.
:
:
2y + 3z u = 2
2x + y z + u = 0
|
|
x + 3y 4z + 2u = 1
x + y + z = 1
1 -2 3 -1 (- 2) (- 1) 1 -2 3 -1 2
2 1 -1 1 + 0 5 -7 3 -4 (- 1) (- 3)
= 1 3 -4 2 + ó 0 5 -7 3 -1 + ó
1 1 1 0 + 0 3 -2 1 -1 5 +
1 -2 3 -1 2 1 -2 3 -1 2
0 5 -7 3 -4 0 5 -7 3 -4
0 0 0 0 3 ó 0 0 11 -4 7
0 0 11 -4 7 0 0 0 0 3
x 2y + 3z u = 2
5y 7z + 3u = -4
11z 4u = 7
0 = 3
, .. , . , .
: .
, , , . , , . , , . .
: :
x + y + z + u = 2
2x + y + 2z + 2u = 3
x + z + u = 1
3x + 2y + 3z + 3u = 5
1 1 1 1 2 (- 2) (- 1) (- 3) 1 1 1 1 2
2 1 2 2 3 + 0 -1 0 0 -1 (- 1)
A = 1 0 1 1 1 + ó 0 -1 0 0 -1 + ó
3 2 3 3 5 + 0 -1 0 0 -1 +
1 1 1 1 2 +
0 -1 0 0 -1 1 0 1 1 1 1 0 1 1 1
0 0 0 0 0 ó 0 -1 0 0 -1 (- 1) ó 0 1 0 0 1
0 0 0 0 0
x + z + u = 1
y = 1
z u
= 1 1 2
y = 1
: z = c1
u = c2, c1, c2 - .
:
z u . ( y) . . z u. :
x = c1 = 1
y = 1 y = 1
z = c2 z = 1 c1 c2
u = 1 c1 c2 u = c2
, , , , , .