Bài tập cơ bản phương trình vô tỷ dành cho các em học sinh lớp 9 tự giải ôn luyện chuyên đề thường xuất hiện trong các đề thi vào 10 này.
Bài 1: Giải các phương trình sau:
1. sqrtx2−6x+9=x
2. sqrt4x2−12x+9=x−1
3. x+sqrt4x2−4x+1=2
4. 1−sqrt4x4−20x2+25=0
5. x2−sqrtx2=0
6. x2+sqrtx2=0
7. x+sqrtx2−4x+4=0
8. x−sqrt4x2−12x+9=0
9. 3x−1−sqrt4x2−12x+9=0
10. x−sqrt4x2−12x+9=3
11. sqrt3−2sqrt2−sqrtx2+2xsqrt3+3=0
12. sqrt5x2−2xsqrt5+1=sqrt6−2sqrt5
13.sqrt4x2+4xsqrt7+7−sqrt8−2sqrt7=0
14. sqrt7−2sqrt10−sqrt5x2−2xsqrt10+2=0
15. sqrt11+6sqrt2=sqrt2x2−6xsqrt2+9
16. sqrt11−sqrt120=sqrt5x2+xsqrt120+6
17. sqrt1+2xsqrt3+3x2−sqrt3+2xsqrt3+x2=0
18. sqrt5x2−2xsqrt5+1−sqrt4x2+4xsqrt5+5=0
19. sqrt16x2+8xsqrt2+2−sqrt9x2−6xsqrt2+2=0
20. sqrt2x2−2xsqrt6+3−sqrt2−2xsqrt6+3x2=0
21. sqrt8x2−4xsqrt2+1−sqrtx2−6xsqrt2+18=0
22. sqrt5x2+2xsqrt30+6−sqrt6x2+2xsqrt30+5=0
23. sqrtx2=x
24. sqrtx2−2x+1=x−1
25.sqrtx2−4x+4=x−2
26. sqrt16−8x+x2=4−x
27. sqrt4x2−12x+9=2x−3
28. sqrt25x2−10x+x=5x−1
29. sqrtx2−2xsqrt5+5=x−sqrt5
30. sqrt3x2−6xsqrt2+6=sqrt3x−sqrt6
31. sqrt10x2−12xsqrt10+36=sqrt10x−6
32. sqrt7x2+2xsqrt14+2=sqrt7x+sqrt2
33. sqrtx2=−x
34. sqrtx2−6x+9=3−x
35. sqrtx2−4x+4=2−x
36. sqrtx2+4x+4=−x−2
37. sqrt4x2+4x+1=−2x−1
38. sqrtx2+x+frac14=−x−frac12
39. sqrtx+2sqrtx+1−sqrtx−2sqrtx+1=2
40. sqrtx+4sqrtx+4+sqrtx−4sqrtx+4=4
41. sqrtx+6sqrtx+9−6=sqrt9−6sqrtx+x
42. sqrt4x+4sqrtx+1=sqrt1−4sqrtx+4x+2
43. sqrtx−2sqrtx−1−sqrtx+2sqrtx−1=−2
44. sqrtx−2sqrtx−2−1−sqrtx+2+4sqrtx−2+3=0
45. −sqrtx+3+4sqrtx−1+sqrtx+8−6sqrtx−1=−5
46. sqrtx+4sqrtx−4−sqrtx−4sqrtx−4=4
47. −sqrt2x+4+6sqrt2x−5+sqrt2x−4−2sqrt2x−5=−4
48. 4+sqrt2x+6−6sqrt2x−3=sqrt2x−2+2sqrt2x−3
49. sqrtx+2sqrtx+1+sqrtx−2sqrtx+1=2
50. sqrtx−2sqrtx−1+sqrtx+2sqrtx−1=2
51. sqrtx−2sqrtx−2−1+sqrtx+2+4sqrtx−2−3=0
52. sqrtx+3+4sqrtx−1+sqrtx+8−6sqrtx−1=5
53. sqrtx+4sqrtx−4+sqrtx−4sqrtx−4=4
54. sqrt2x+4+6sqrt2x−5+sqrt2x−4−2sqrt2x−5=4
55. sqrt2x+2sqrt2x+1−sqrt2x−2sqrt2x+1=2
56. sqrt4+4sqrt3x+3x−4=sqrt4−4sqrt3x+3x
57. sqrt12x−4sqrt3x+1−sqrt1+4sqrt3x+12x=−2
58. sqrt18x+6sqrt2x+1−sqrt1−6sqrt2x+18x=2.
Bài 2: Giải các phương trình sau:
1. sqrt2x−3=sqrtx−1
2.sqrt2x−3−sqrtx+3=0
3. sqrtx−1=sqrt2x+3
4. sqrt2x−3=sqrtx+1
5. sqrtx+2=sqrt2x−4
6. sqrt2−x=sqrt3+x
7. sqrt1−x−sqrtx−3=0
8. sqrt−2x−sqrt2−x=0
9. sqrt6−x−sqrt−3x=0
10. sqrtx2−3x−sqrt5left(3−xright)=0
11. sqrtx−2=sqrtx−2
12. displaystylesqrt4x−8=2sqrtx−2
13. sqrtx−1−sqrtx−4=0
14. sqrt2−x−sqrt3−x=0
15. sqrtx2−5=sqrt4x−9
16. sqrt2x2−6x+2=sqrtx2−3x
17. sqrtx2−2x−4=sqrt2−x
18. sqrtx2−x−1=sqrtx−1
19. sqrtx−2−sqrtx2−2x=0
20. sqrtx2−x−2=sqrtx+1
21. sqrt2x2−10x+11=sqrtx2−6x+8
22. sqrt2x2+6x−3=sqrtx2+4x
23. sqrt2x2+x−9=sqrtx2−x−6
24. sqrtx−1=2
25. sqrt2x−3=13
26. sqrt2x−3=sqrt2
27. sqrtxleft(x−2right)−sqrt3=0
28. 3sqrtx=−1
29. sqrtx−1+2=0
30. 6−sqrt2x+3=12
31. 3sqrtx2−x−sqrt54=0
32. 2sqrt2−sqrtx2+2x=0
33. 2sqrt3−sqrt7x−x2=0
34. 3−sqrtx2+3=0
35. 2−sqrtxleft(4−xright)=0
36. 3−sqrt−xleft(x+6right)=0
37. 2−sqrtx2−1=0
38. 1−sqrtx2−2=0
39. sqrt16−2sqrtx2+3x=0
40. 2sqrt3−sqrtxleft(x+7right)=0
41. sqrt3−x=3x−5( PTNK, CD, 1999-2000)
42. x−sqrt4x−3=2 ( PTNK, AB, 2004-2005, Vòng 1)
43. sqrtx2−x=x
44. sqrtx2−1=x−1
45. sqrt3−x2=x
46. sqrtx2−2x+2=x−1
47. sqrt5−x2=x−1( LÊ HỒNG PHONG, 2006-2007, Vòng 1)
48. x−2=sqrtx2−4x+3
49. sqrtx−x=0
50. sqrtx+x=0
51. x−sqrt2x−9=6
52. 2x−sqrt4x−1=0
53. 3x−sqrt6x−1=0
54. x−2sqrtx−1=16
55. x+sqrt−left(2x+1right)=0
56. x+2sqrtx−1=0
57. x+sqrt3left(6−xright)=0
58. x+sqrtx+3=0
59. x+sqrt2x+3=0
60. x+sqrt5−4x=0
61. 2x+sqrt3x+7=0
62. 3x+sqrt5x+4=0
63. 2x−sqrtxleft(1−2xright)=1
64. x+sqrt1−x2=1
65. x+sqrt4−x2=2
66. 2x+sqrt4left|xright|−1=0
67. x+2sqrtleft|xright|−1=0
68. −5x+sqrt2left|xright|+3=0
69. 3sqrt−2left|xright|+1=9x
70. 7x+sqrtleft|xright|−4=0
71. sqrt10left|xright|−10−6x=0
72. sqrt−3left|xright|+2+1=x
73. sqrt7left|xright|+11+x+1=0
74. sqrt2left|x−1right|−3−x+1=0
75. −3sqrt2left|2x+1right|−5+6x+3=0
76. 5sqrt2left|1−5xright|+3−5+25x=0
77. −2sqrt−8left|2−3xright|+9+4−6x=0
78. 7sqrt−4left|3x−9right|+5+21x−63=0
79. sqrt−2left|1−2xright|+3+1=2x
80. displaystyle3sqrt2x−5sqrt8x+7sqrt18x=8
81. frac53sqrt15x−sqrt15x+11=frac13sqrt15x
82. sqrt4x+20−sqrtx+5−frac13sqrt9x+45=4
83. sqrt36x−36−sqrt9x−9−sqrt4x−4=16−sqrtx−1
84. sqrt36x−72−sqrt9x−18+sqrt4x−8+sqrtx−2=sqrt72
85. sqrt9x+18−sqrtx+2−sqrt4x+8+2sqrtx+5=0
86. frac53sqrt45x−sqrt125x−frac13sqrt405x−2sqrt16−16x=0
87. frac15sqrt25x−125−frac32sqrtx−5+sqrt36x−180+sqrt9x−27=0
88. sqrt36x−216−sqrtx−6+frac72sqrt4x−24=frac37sqrt49x−343
89. 15sqrtx−7−2sqrt9x−63−9sqrt25x−175=sqrt4x−24
90. displaystylesqrt49x−98−sqrt9x−18−sqrt16x−32=sqrt4x−4
91. 7sqrtx+sqrt81x−81+sqrtx−1=sqrt100x−100
92. sqrtx2−2xsqrt5+5+sqrtx2−xsqrt5=0
93. sqrt0,2x2−2x+5+sqrt3x2−15x=0
94. sqrtx2+4x+sqrtfracx22−8=0
95. sqrtx−1+sqrtx2−3x+2=0
96. sqrt2+x+sqrt4x2−6x−10=0
97. sqrtx2−9+sqrtx2−4x+3=0
98. sqrt−2x2+3x+5+sqrt2x2−7x−15=0
LUYỆN TẬP
Bài 3: Giải các phương trình sau:
1. x2+4left(left|x−2right|−xright)−1=0
a) Đặt t=left|x−2right| để đưa phương trình trên về phương trình theo ẩn t.
b) Tìm t rồi sau đó tìm x.
2. x2+2left(left|x−1right|−xright)−2=0
3. x2+3left(left|x−3right|−2xright)−9=0
4. x2+4left(left|x−4right|−2xright)+4=0
5. x2+left(x+left|x+1right|right)−14=0 (PTNK BAN CD 2006-2007)
6. 7−4sqrt2x−1=3left|1−2xright|
a) Đặt t=sqrt3−2x để đưa phương trình trên về phương trình theo ẩn t.
b) Tìm t rồi sau đó tìm x.
7. 5−sqrt3−2x=left|2x−3right| (PTNK BAN CD 2000-2001)
8. 20−sqrt3−2x=left|2x−3right| (PTNK BAN CD 2004-2005)
9. 12−sqrt4−3x=left|3x−4right| (PTNK BAN CD 2007-2008)
10. left|1−2xright|=6−sqrt2x−1
11. 2left|4−3xright|+3sqrt3x−4−2=0
12. 3left|3x−1right|+8sqrt1−3x=3
13. 2sqrtfrac6x−12x=frac2x6x−1+1
a) Đặt t=sqrtfrac6x−12x để đưa phương trình trên về phương trình theo ẩn t.
b) Tìm t rồi sau đó tìm x.
14. 2sqrtfrac3x−1x=fracx3x−1+1 (PTNK BAN CD 2001-2002)
15. 2sqrtfrac6x−12x=frac2x6x−1+1
16. 2sqrtfrac9x−13x=frac3x9x−1+1
17. 2sqrtfrac3x−3x=frac3xx−1+1
18. sqrtfrac6x−4x=fracx3x−2+1
19. sqrtfrac2x−1x+1+sqrtfracx2x−1=3fracx2x−1
20. 2sqrtfracxx−1−sqrtfracx−1x=2fracx−1x+3
21. 3sqrtfrac2xx−1+4sqrtfracx−12x=3fracx−12x+10
22. sqrtfracx3−2x+5sqrtfrac3−2xx=4frac3−2xx+5
23. 2sqrtfrac2x+1x−3sqrtfracx2x+1=4fracx2x+1+7
24. frac2+sqrt19−2xx=1
25. sqrtx−frac4sqrt2+x+sqrt2+x=0
26. sqrt9−5x=sqrt3−x+frac6sqrt3−x
27. sqrt2−x+frac43+sqrt2−x=2
28. fracleft(5−xright)sqrt5−x+left(x−3right)sqrtx−3sqrt5−x+sqrtx−3=2
Bài 4: Giải các phương trình sau:
1. sqrt2x+3+sqrt2x+2=1
2. sqrt1−x+sqrt4+x=3
3. sqrtx+4−sqrt2x−6=1 ( PTNK, AB, 2006-2007, Vòng 1)
4. sqrt3x−5+sqrt2x+3=sqrtx+2 (HSG, Q. Tân Bình, 2003-2004)
5. sqrtx−2+sqrtx−1=sqrt2x−3 ( LÊ HỒNG PHONG 2001-2002, Vòng 1)
6. sqrt3x+7−sqrtx+1=2
7. sqrtx+3+sqrtx−1=2
8. sqrtx+5+sqrt3−x=4
9. sqrtx2+9−sqrtx2+7=2
10. sqrt2−x2+sqrtx2+8=4
11. sqrtx+3−sqrt7−x=sqrt2x−8
12. sqrt2−x=sqrt7−x−sqrt−3−2x
13. sqrt11−x−sqrtx−1=2
14. sqrtx2+3x+2−sqrtx2+x+1=1
15. sqrt5x−1=sqrt3x−2−sqrt2x−3
16. sqrt5x−1−sqrtx−1=sqrt2x−4
17. sqrtx+2−sqrt2x−3=sqrt3x−5 (HSG, Q.I,1999-2000)
18. sqrtx+4−sqrt1−x=sqrt1−2x
19. sqrtx+9=5−sqrt2x+4
20. sqrt3x+4−sqrt2x+1=sqrtx+3
21. sqrtx+12+sqrtx−6−sqrtx+2−sqrtx−4=0
22. sqrt3x+6+sqrt3x−3−sqrt3x+1−sqrt3x−2=0
23. sqrtx+4+sqrtx−5−sqrtx−1−sqrtx−4=0
24. sqrt2x+6+sqrt2x−3−sqrt2x+1−sqrt2x−2=0
25. sqrtx+6+sqrtx−3−sqrtx+1−sqrtx−2=0 (PTNK, AB, 2005-2006, Vòng 1)
26. left{ begin{array}{l}x-y=5sqrt{2x+1}-sqrt{y+2}=2end{array} right. ( PTNK, AB, 2005-2006, Vòng 1)
27. sqrtx+sqrtx+11+sqrtx−sqrtx+11=4
28. sqrtx−sqrtx−2+sqrtx+sqrtx−2=3
29. frac2−sqrtx2−x=sqrtfrac22−x
30. sqrtfrac20+xx+sqrtfrac20−xx=sqrt6 ( đặt t=frac20x)
Bài 5: Giải các phương trình sau:
1. sqrt2x+1+sqrtx−3=2sqrtx
2. sqrtx+2−sqrt2x−3=sqrt4x−7
3. sqrtx+sqrtx−3=sqrt3left(x−1right)
4. sqrtx−2+sqrt4−x=sqrt6−x
5. sqrtx+5=2sqrtx−sqrt2x−7
6. sqrt3x+12−sqrt4x+13=sqrtx+1
7. sqrt9−x−sqrtx+4=sqrt3x+1
8. sqrt3x+4=2sqrtx−sqrtx−4
9. sqrt2x+5=sqrt12x+25−sqrt5x+6
10. sqrtx+1+sqrtx−1=sqrt3x−1
11. sqrt3x−5+sqrt2x−3=sqrtx+2
12. sqrtx2+9−sqrtx2−7=2
13. sqrtx2+5+sqrtx2−3=4
14. sqrtx2−3x+6+sqrtx2−3x+3=3
15. sqrt3x2−2x+15+sqrt3x2−2x+8=7
16. sqrt3x2+5x+8−sqrt3x2+5x+1=1
Bài 6: Giải các phương trình sau:
1. sqrtx+6+sqrtx−3−sqrtx+1−sqrtx−2=0
2. sqrtx2+x−5+sqrtx2+8x−4=5
3. sqrt3x2+6x+16+sqrtx2+2x=2sqrtx2+2x+4
4. sqrt2x2−9x+4+3sqrt2x−1=sqrt2x2+21x−11
Bài 7: Giải các bất phương trình sau:
1. sqrt3x−5x2le5x−2 (PTNK, AB, 2006-2007, Vòng 1)
2. sqrt5−xle2x−7
3. sqrtx+1<2x−1 (PTNK, AB, 2002-2003, Vòng 1)
4. sqrtx2−x−12<7−x
5. 1−x+sqrt2x2−3x−5<0
6. sqrtx2−3x−10lex−2
7. 3sqrt−x2+x+6+2left(2x−1right)<0
8. sqrt3x2+13x+4+2−xle0
9. 2sqrt3x+x2le2x−1
10. sqrtx2−3x+3le2x−1
11. sqrtx2+3x−3le2x−3
12. −6x+7gesqrtx2−6x+7
13. sqrtx2−3x−10le8−x
14. sqrtx2+5x−6<2x+3
15. sqrtx+3<x+1
16. sqrt2x+12<x+2
17. displaystylesqrtx2−6x−40le16−x
18. sqrtx2+10x+4le2x−4
19. 3sqrt−x2+3x+54+4x−6<0
20. 2−x+sqrt2x2−6x−20<0
Bài 8: Giải các bất phương trình sau:
1. sqrt3x−5x2ge5x−2
2. sqrt5−xge2x−7
3. sqrtx+1ge2x−1
4. sqrtx2−x−12ge7−x
5. 1−x+sqrt2x2−3x−5>0
6. sqrtx2−3x−10gex−2
7. 3sqrt−x2+x+6+2left(2x−1right)>0
8. sqrt3x2+13x+4+2−xge0
9. 2sqrt3x+x2ge2x−1
10. sqrtx2−3x+3ge2x−1
11. sqrtx2+3x−3le2x−3
12. −4x+2le4sqrtx2−6x+5
13. sqrtx2−3x−10ge8−x
14. sqrtx2+5x−6>2x+3
15. sqrtx+3>x+1
16. sqrt2x+12>x+2
17. displaystylesqrtx2−6x−40ge16−x
18. sqrtx2+10x+4ge2x−4
19. 3sqrt−x2+3x+54+4x−6>0
20. 2−x+sqrt2x2−6x−20>0