Bài tập hệ phương trình
Giải các hệ phương trình sau :
1, 2,
++=−
⎧
−
⎨
+=−
⎩
22
1
(
6
xxyy
MTCN
xy yx
99)
8)
3)
⎧
+=
⎪
−
⎨
−+=
⎪
⎩
22
4224
5
(9

55 22
1
( 97)
xy
AN
xyxy
5, 6,
⎧
++=
⎪
−
⎨
++ =
⎪
⎩
22
4422
7
( 1 2000)
21
xyxy
SP
xyxy
++ =
⎧
−
⎨
++ +=
⎩
22

−
⎨
⎪
++ =
⎪
⎩
22
22
1
()(1)5
(9
1
()(1)49
xy
xy
NT
xy
xy
9)

9,
⎧
++ + =
⎪
⎪
−
⎨
⎪
++ + =
⎪

+++++ ++++=
⎪
−
⎨
+++−+ +++−=
⎪
⎩
22
22
1118
(9
112
xxy x yxy y
AN
xxy x yxy y
9)
8)

12, 13,
++=
⎧
−
⎨
++−=
⎩
2
(3 2 )( 1) 12
( 97)
2480
xx yx

HVQHQT
xyxy
⎧
−=−
⎪
−
⎨
−=−
⎪
⎩
22
22
23 2
( 2000)
23 2
xxy
QG
yyx
16, 17,
⎧
=−
⎪
−
⎨
=−
⎪
⎩
2
2
3

=+
⎪
−
⎨
=+
⎪
⎩
3
3
38
(9
38
xxy
QG
yyx
⎧
+=
⎪
⎪
−
⎨
⎪
+=
⎪
⎩
2
2
3
2
( 2001)

2
3
y
y
x
x
x
y
⎧
+
=
⎪
⎪
⎨
+
⎪
=
⎪
⎩

22,
⎧
−=
⎪
−
⎨
−−=
⎪
⎩
2

−
⎨
−+=
⎪
⎩
22
22
239
()
21315 0
xxyy
H
VNH TPHCM
xxyy
25,
⎧
−=
⎪
−
⎨
+=
⎪
⎩
22
22
2( ) 3
(§ 97)
()10
yx y x
MC

7,
22 1 1xxx++ +− +=4
8,
2 1 2 1 2( 2000 )xx xx BCVT+−−−−= −

9,
3(2 2) 2 6( 01 )xxxHVKTQS+−=++ −

10,
22
2 8 6 1 2 2( 2000)xx x xBK+++ −=+ −
11,
22 22
55
1 1 1( 2001)
44
x x x x x PCCC−+− + −−− =+ −

12,
2
( 1) ( 2) 2 ( 2 2000 )xx xx x SP A−+ + = −
13,
22
286 122( 99x x x x HVKTQS+++ −=+ −)
Tìm m để phương trình :
14,
2
22 1
x
mx x++=+ có 2 nghiệm phân biệt

1 4 ( 1)(4 )( 20001)xxxxNN++ − + + − −

24,
22
4234
x
xx+−=+ −x
25,
2
24 61xxxx−+ −= − +1

26,
2
2 3 5 2 4 6 0( 01)xxxxGTVTTPHCM−+ − + − −= − −

27,
2
3 2 1 4 9 2 3 5 2( 97)xxx xxHVKTQS−+ −= −+ − + −
28,
2
74
4
2
xx
x
x
++
=
+
29,

22
31(3) 1( 01xx x x GT++=+ + −) 34,
22
2(1) 21 21xx x x x
−
+−=−−
35,
2
11( 98)xx XD++= −
36,
3
2 1 1( 2000)xxTCKT−=− − −

37,
3
7xx+− =1 38,
33
33
75
6
75
xx
x
xx
−− −
=
−
−+ −
39,
3

2
4( 01)
(1 1)
x
xSPVinh
x
>− −
++
8,
22
12 12
11 2 9
x
xx
xx
x
+
−+
≥
−−
−

9,
22 2
3 2 6 5 2 9 7( 2000)xx xx xxBK+++ ++≤ ++ −
10,
22
43 2 31 1( 2001xx xx xKT−+− −+≥− − )
11,
22