(2x+5)2=(x+2)2
<=> (2x+5)2-(x+2)2=0
<=> (2x+5-x-2)(2x+5+x+2)=0
<=> (x+3)(4x+7)=0
<=>\(\left[{}\begin{matrix}x+3=0\\4x+7=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=-3\\x=\dfrac{-7}{4}\end{matrix}\right.\)
Vậy S= \(\left\{-3;\dfrac{-7}{4}\right\}\)
Giải phương trình:
b) (x+2) (2x^2-5) - (x^3-8) = 0
c) x-5/x-1 + 2/x-3 = 1
d) 2x+5/x+3 + 1 = 4/x^2+2x-3 - 3x-1/1-x
Bài 1: Giải các phương trình sau:
Câu 1.
a) 3x – 2 = 2x – 3 b) 3 – 4y + 24 + 6y = y + 27 + 3y
c) 7 – 2x = 22 – 3x d) 8x – 3 = 5x + 12
e) x – 12 + 4x = 25 + 2x – 1 f) x + 2x + 3x – 19 = 3x + 5
g) 11 + 8x – 3 = 5x – 3 + x h) 4 – 2x + 15 = 9x + 4 – 2x
2. a) 5 – (x – 6) = 4(3 – 2x) b) 2x(x + 2)2 – 8x2 = 2(x – 2)(x2 + 2x + 4)
c) 7 – (2x + 4) = – (x + 4) d) (x – 2)3 + (3x – 1)(3x + 1) = (x + 1)3
e) (x + 1)(2x – 3) = (2x – 1)(x + 5) f) (x – 1)3 – x(x + 1)2 = 5x(2 – x) – 11(x + 2)
g) (x – 1) – (2x – 1) = 9 – x h) (x – 3)(x + 4) – 2(3x – 2) = (x – 4)2
i) x(x + 3)2 – 3x = (x + 2)3 + 1 j) (x + 1)(x2 – x + 1) – 2x = x(x + 1)(x – 1)
3. a) 1,2 – (x – 0,8) = –2(0,9 + x) b) 3,6 – 0,5(2x + 1) = x – 0,25(2 – 4x)
c) 2,3x – 2(0,7 + 2x) = 3,6 – 1,7x d) 0,1 – 2(0,5t – 0,1) = 2(t – 2,5) – 0,7
e) 3 + 2,25x +2,6 = 2x + 5 + 0,4x f) 5x + 3,48 – 2,35x = 5,38 – 2,9x + 10,42
4.a) (5x-2)/3=(5-3x)/2 b)(10x+3)/12=1+((6+8x)/9)
c)2(x+3/5)=5-(13/5+x) d)7/8x-5(x-9)=(20x+1,5)/6
e)(7x-1)/6+2x=(16-x)/5 f)4(0,5-1,5x)=-(5x-6)/3
g)(3x+2)/2-(3x+1)/6=5/3+2x h)(x+4)/5-(x+4)=x/3-(x-2)/2
i) (4x+3)/5-(6x-2)/7=(5x+4)/3+3 k)(5x+2)/6-(8x-1)/3=(4x+2)/5-5
m)(2x-1)/5-(x-2)/3=(x+7)/15 n)1/4(x+3)=3-1/2(x+1)-1/3(x+2)
Bài 2 Tìm giá trị của k sao cho:
a. Phương trình: 2x + k = x – 1 có nghiệm x = – 2.
b. Phương trình: (2x + 1)(9x + 2k) – 5(x + 2) = 40 có nghiệm x = 2
c. Phương trình: 2(2x + 1) + 18 = 3(x + 2)(2x + k) có nghiệm x = 1
giải phương trình
a, \(\dfrac{3}{2x-1}+1=\dfrac{2x-1}{2x+1}\)
b,\(\dfrac{3x-1}{x-1}-\dfrac{2x+5}{x+3}+\dfrac{4}{x^2+2x-3}=1\)
c,\(\dfrac{5}{x^2+x-6}-\dfrac{2}{x^2+4x+3}=\dfrac{-3}{2x-1}\)
d, \(\left(x^2-4\right)\left(2x+3\right)=\left(x^2-4\right)\left(x-1\right)\)
e, \(x^3+x^2+x+1=0\)
x+5/x^2-5x - x-5/2x^2+10x=x+25/2x^2-50
Bài 8:Giải cácphương trình sau.
a) (3x – 2)(4x + 5) = 0 b) 2x(x – 3) + 5(x – 3) = 0
c) (2x + 1)(3x – 2) = (5x – 8)(2x + 1) d) 3x – 15 = 2x(x – 5)
e) x(2x – 9) = 3x(x – 5) f) (x + 2)(3 – 4x) = x2 + 4x + 4
g) (x –\(\sqrt{2}\)) + 3(x2 – 2) = 0 h) (2x – 5)2 – (x + 2)2 = 0
i) 2x3 + 5x2 – 3x = 0 k) 2x2 – 6x + 1 = 0
Bài 5:Giải các phương trình sau.
a) 3 – 4y + 24 + 6y = y + 27 + 3y b) 5 – (x – 6) = 4(3 – 2x)
c) (x + 1)(2x – 3) = (2x – 1)(x + 5) d) 2x(x + 2)2 – 8x2 = 2(x – 2)(x2 + 2x + 4)
e) (x – 3)(x + 4) – 2(3x – 2) = (x – 4)2 f) (x + 1)(x2 – x + 1) – 2x = x(x + 1)(x – 1)
Giải các phương trình sau :
a) | x2 - x | = -2x
b) 2x+3/ 3 - x = 5 + x+1/ 2
c) 2/x2+2x+1 - 5/x2 -2x+1 = 3/1-x2
Giai pt
- \(\frac{x+5}{x^2-5x}-\frac{x-5}{2x^2+10x}=\frac{x+25}{2x^2-50}\)
- \(\dfrac{\left(x+2\right)^2}{2x-3}-1=\dfrac{x^2+10}{2x-3}\)
1) 4x-10=0 2) 2x^3 + 6x^2 = x^2 + 3x 3) x - 5 = 3 - x 4) (-10x + 5 ) ( 2x - 8 ) = 0
Giải phương trình:
a) 1/x2 +4x + 3 + 1/x2 + 8x + 15 + 1/x2 + 12x + 35=1/9
b) 12x + 1/ 6x-2 - 9x-5/3x +1 = 108x - 36x2 - 9/4.(9x2 -1)
c) 3x-1/x-1 - 2x+5/x+3 = 1- 4/x2 +2x - 3
d) x2 + 2x + 1/x2 + 2x +2 + x2 +2x + 2/ x2 + 2x +3 = 7/6
