a, Đặt (x2 +x ) = t ta có:
=> t2 + 4t - 12 = 0
=> ( t + 2)2 - 16 = 0
=> ( t + 2)2 - 42 = 0
=> ( t -2)( t + 6) = 0
=>\(\left[{}\begin{matrix}t-2=0\\t+6=0\end{matrix}\right.\)
Thay t = x2 + x
- x2 + x -2 = 0 => (x+2)(x-1) = 0 => \(\left[{}\begin{matrix}x=-2\\x=2\end{matrix}\right.\)
- x2 + x + 6 = 0 => (x+3)(x-2) = 0 => \(\left[{}\begin{matrix}x=-3\\x=2\end{matrix}\right.\)
Giải pt sau:
1) (9x2-4)(x+1)=(3x+2)(x2-1)
2) (x-1)2-1+x2=(1-x)(x+3)
3) x2-7x+6=0
4) x4 -4x3+12-9=0
5) (x2+x)2+4(x2+x)-12=0
6) x(x+1)(x2+x+1)=42
7) (x+2)(x-2)(x2-10)=72
8) (x-1)(x-3)(x+5)(x+7)-297=0
9) 4(2x+7)2-9(x+3)2=0
10) x4-2x2-144x-1295=0
Bài 1: Giải các phương trình sau
a, x-5=3-x
b, 7-3x= 9-x
c, 7x-8= 4x+7
d, 2x+5=20-3x
e, 5y+12=8y+27
f, 13-2y=y-2
g, 0,1x- 0,27=x
Bài 2: Giải PT sau
a, 2x-(3-5x)=4(x+3)
b, (x-2)2-x(x+5)= 9
c, (x-3)(x+2)+ (5-x) (x-1)= 0
d, x(4x-2)-( 2x+3)2= 5
e,5-(x-6)=4(3-2x)
Bài 3: Giải PT sau
a, (x-1)(3x+2)=0
b, (2x+5)(x-2)=0
c, (x+1)(x2+1)=0
d, x(2x-9)= 3x(x-5)
e, x(x-2)-x2+4=0
f, (x+3)2-2x-6=0
g,3x-15=3x(x-5)
h, (x2-2x+1)-4=0
i,x2-5x+6=0
j, ( 3x+1)(x2+2)= (3x+1)(7x-10)
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a) (x-1)* (x-3) *(x+5)*(x +7) - 297 = 0
b) x4 - 2x2 + 144x - 1295 = 0
c) \(\dfrac{1927-x}{91}+\dfrac{1925-x}{93}+\dfrac{1923-x}{95}+\dfrac{1921-x}{97}+4=0\)
d) \(\dfrac{x-85}{15}+\dfrac{x-74}{13}+\dfrac{x-67}{11}+\dfrac{x-64}{9}=10\)
Giải các phương trình sau:
a/ (2x+1)(x2+2)=0
b/ (x2+x+1)(6-2x)=0
c/ (x-5)(3-2x)(3x+4)=0
d/ (x2+4)(7x-3)=0
e/ (8x-4)=(x2+x+2)
f/ (2x-1)(3x+2)(5-x)
Dạng 1: Phương trình bậc nhất
Bài 1: Giải các phương trình sau :
a) 0,5x (2x - 9) = 1,5x (x - 5)
b) 28 (x - 1) - 9 (x - 2) = 14x
c) 8 (3x - 2) - 14x = 2 (4 - 7x) + 18x
d) 2 (x - 5) - 6 (1 - 2x) = 3x + 2
e) \(\frac{x+7}{2}-\frac{x-3}{5}=\frac{x}{6}\)
f) \(\frac{2x-3}{3}-\frac{5x+2}{12}=\frac{x-3}{4}+1\)
g) \(\frac{x+6}{2}+\frac{2\left(x+17\right)}{2}+\frac{5\left(x-10\right)}{6}=2x+6\)
h) \(\frac{3x+2}{5}-\frac{4x-3}{7}=4+\frac{x-2}{35}\)
i) \(\frac{x-1}{2}+\frac{x+3}{3}=\frac{5x+3}{6}\)
j) \(\frac{x-3}{5}-1=\frac{4x+1}{4}\)
Dạng 2: Phương trình tích
Bài 2: Giải phương trình sau :
a) (x + 1) (5x + 3) = (3x - 8) (x - 1)
b) (x - 1) (2x - 1) = x(1 - x)
c) (2x - 3) (4 - x) (x - 3) = 0
d) (x + 1)2 - 4x2 = 0
e) (2x + 5)2 = (x + 3)2
f) (2x - 7) (x + 3) = x2 - 9
g) (3x + 4) (x - 4) = (x - 4)2
h) x2 - 6x + 8 = 0
i) x2 + 3x + 2 = 0
j) 2x2 - 5x + 3 = 0
k) x (2x - 7) - 4x + 14 = 9
l) (x - 2)2 - x + 2 = 0
Dạng 3: Phương trình chứa ẩn ở mẫu
Bài 3: Giải phương trình sau :
| \(\frac{90}{x}-\frac{36}{x-6}=2\) | \(\frac{3}{x+2}-\frac{2}{x-3}=\frac{8}{\left(x-3\right)\left(x+2\right)}\) |
| \(\frac{1}{x}+\frac{1}{x+10}=\frac{1}{12}\) | \(\frac{1}{2x-3}-\frac{3}{x\left(2x-3\right)}=\frac{5}{x}\) |
| \(\frac{x+3}{x-3}-\frac{1}{x}=\frac{3}{x\left(x-3\right)}\) | \(\frac{3}{4\left(x-5\right)}+\frac{15}{50-2x^2}=\frac{-7}{6\left(x+5\right)}\) |
| \(\frac{3}{x+2}-\frac{2}{x-2}+\frac{8}{x^2-4}=0\) | \(\frac{x}{x+1}-\frac{2x-3}{1-x}=\frac{3x^2+5}{x^2-1}\) |
Giải các phương trình sau bằng cách đưa về dạng ax + b = 0 :
1. a) 5 - (x - 6) = 4(3 - 2x)
b) 2x(x + 2)^2 - 8x^2 = 2(x - 2)( x^2 + 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)(x^2 - x + 1) - 2x = x(x + 1)(x-1)
1. giải phương trình.
a. (2x+1)(x-1)=0
b. \(\left(x+\frac{2}{3}\right)\left(x-\frac{1}{2}\right)\) (x+2020)=0
c. (3x-1)(2x-3)(2x-3)(x+5)=0
d. 3x-15=2x(x-5)
e. x2-2x+1=0
f. x2+x+\(\frac{1}{4}\) =0
g. x2-3x-4=0
h. (x+1)(x+4)=(2-x)(x+2)
đang gấp, giúp e với ạ
bài 1: giải các pt sau: a, 1/x-2+3=7-x/x-2
b, x^2-x/x+3-x^2/x-3=7x^2-3x/9-x^2
c, x/2x-1 + x+1/x+2=0
d, 2/x+1 - 1/x-2 = 3x-11/(x+1)(x-2)
Bài 1 : Giải các phương trình sau :
1) x – 8 = 3 – 2(x+ 4)
2) 2(x + 3) – 3(x – 1) = 2
3) 4(x – 5) – (3x – 1) = x – 19
4) 7 – ( x – 2) = 5(2x – 3)
5) 32 – 4(0,5y – 5) = 3y + 2
6) 3(x – 1) – x = 2x – 3
7) x2 + 2x – 4 = –12 + 3x + \(x^2\)
8) x( x – 1) – x(x + 3) = 15
9) x( x – 1) = x(x + 3)
10) (x–1)(x +3) – (x+2)(x–3) = 0
11) (x–2)(x –5) – (x–3)(x–4) = 0
12) (3x – 2)(4x + 3) = 2x(6x – 1)
13) \(4x^2\) – (2x + 1)(2x – 1) = 0
14) (4x–5)(x+3) = (2x – 3)(7+2x)
15) (x + 3)(x – 2) = (x + 1)2
16) (x+7)(x–7) + \(x^2\) – 2 = 2(\(x^2\)+5 )
17) \(\left(x-1\right)^2\) + \(\left(x+3\right)^2\) = 2(x– 2)(x+2)
18) \(\left(x-5\right)^2\) = \(\left(x+3\right)^2\) + 2
Mình đang cần , các bạn giúp mình với ạ !!!