(1/√2-1 - 2√2/x√x+√x-x+1) : (1-2√x/x-1)
1) ĐKXĐ: \(x\notin\left\{1;-1\right\}\)
Ta có: \(\dfrac{x+1}{x-1}-\dfrac{x-1}{x+1}=\dfrac{4}{x^2-1}\)
\(\Leftrightarrow\dfrac{\left(x+1\right)^2}{\left(x-1\right)\left(x+1\right)}-\dfrac{\left(x-1\right)^2}{\left(x-1\right)\left(x+1\right)}=\dfrac{4}{\left(x-1\right)\left(x+1\right)}\)
Suy ra: \(x^2+2x+1-\left(x^2-2x+1\right)=4\)
\(\Leftrightarrow x^2+2x+1-x^2+2x-1=4\)
\(\Leftrightarrow4x=4\)
hay x=1(loại)
Vậy: \(S=\varnothing\)
2) ĐKXĐ: \(x\notin\left\{2;-2\right\}\)
Ta có: \(\dfrac{x+2}{x-2}+\dfrac{x}{x+2}=2\)
\(\Leftrightarrow\dfrac{\left(x+2\right)^2}{\left(x-2\right)\left(x+2\right)}+\dfrac{x\left(x-2\right)}{\left(x-2\right)\left(x+2\right)}=\dfrac{2\left(x^2-4\right)}{\left(x-2\right)\left(x+2\right)}\)
Suy ra: \(x^2+4x+4+x^2-2x=2x^2-8\)
\(\Leftrightarrow2x^2+2x+4-2x^2-8=0\)
\(\Leftrightarrow2x-4=0\)
\(\Leftrightarrow2x=4\)
hay x=2(loại)
Vậy: \(S=\varnothing\)
$$ \frac{x^4-(x-1)^2}{(x^2+1)^2-x^2}+\frac{x^2-(x^2-1)^2}{x^2*(x+1)^2-1}+\frac{x^2*(x-1)^2-1}{x^4-(x+1)^2} $$
giải phương trình:
a, 2x-5/x+5=3
b, 2/x-1=6/x+1
c, 2x+1/x-1=5(x-1)/x+1
d, x/x-1 - 2x/x2-1=0
e, 1/x-2 + 3=x-3/2-x
f, x+1/x-2 + x-1/x+2= 2(x2+2)/x2-4
g, x+2/x-2 + 1/x+2=x(x-5)/x2-4
h, 1/x+1 - 5/x+2=15/(x+1)(2-x)
i, x-1/x+2 - x/x-2= 5x-2/4-x2
a,\(2x-5=3x+15\)
\(3x-2x=-5-15\)
\(x=-20\)
b,\(\frac{2}{x-1}=\frac{6}{x+1}\)
\(2x+2=6x-6\)
\(4x=8\)
\(x=2\)
\(\frac{2x+1}{x-1}=\frac{5.\left(x-1\right)}{x+1}\)
\(\frac{2x+1}{x-1}=\frac{5x-5}{x+1}\)
\(2x^2+3x+1=5x^2-10+5\)
\(3x^2-3x=10-5+1=6\)
\(3x.\left(x-1\right)=6\)
\(x.\left(x-1\right)=3\)
Lập bảng
Chứng minh đẳng thức:
a, (x^2-2x/2x^2+8-2x^2/8-4x+2x^2-x^3)(1-1/x-2/x^2)=x+1/2x
b, [2/3x-2/x+1(x+1/3x-x-1)]:x-1/x=2x/x-1
c, [2/(x+1)^3(1/x+1)+1/x^2+2x+1(1/x^2+1)]:x-1/x^3=x/x-1
1/x-1-x^3-x/x^2+1(x/x^2-2x+1-1/x^2-1)
[2/(x+1)^3.(1/x+1)+1/x^2+2x+1(1/x^2+1)]:x-1/x^3=x/x-1
(x/x^2-36-x-6/x^2+6x):2x-6/x^2+6x+x/6-x
giúp mik với ;-; mik cần gấp
giải phương trình:
a) 2/x+1 - 1/x-3= 3x-11/x^2-2x-3
b) 3/x-2 +1/x=-2/x.(x-2)
c) x-3/x+3 - 2/x-3=3x+1/9-x^2
d) 2/x+1 - 1/x-2=3x-5/x^2-x-2
e) x-2/x+2 + 3/x-2=x^2-11/x^2-4
f) x+3/x+1 + x-2/x=2
g) x+5/x-5 - x-5/x+5=20/x^2-25
h) x+4/x+1 + x/x-1=2x^2/x^2-1
i) x+1/x-1 - 1/x+1=x^2+2/x^2-1
Bài 1:Tìm x,biết:
a,(x-2)(x+2)-(x-3)\(^2\)=9
b,(x-1)(x\(^2\)+1)-(x+1)(x\(^2\)-x+1)=x(2-x)
c,(x-3)(x\(^2\)+3x+9)+x(x+2)(2-x)=1
d,(x+1)\(^3\)-(x-1)\(^{^{ }3}\)-6(x-1)\(^2\)=-19
Bài 2:Viết về dạng bình phương hoặc dạng tích:
a,\(\dfrac{1}{27}\)x\(^3\)+x\(^2\)+9x+27
b,8u\(^3\)-60u\(^2\)v+150uv\(^2\)-125v\(^3\)
c,x^3+3x^2+3x+1+3(x^2+2x+1)y+3xy^2+3y^3+y^3
a. (x - 2)(x + 2) - (x - 3)2 = 9
<=> x2 - 22 - (x - 3)2 = 32
<=> x - 2 - (x - 3) = 3
<=> x - 2 - x + 3 = 3
<=> x - x = 3 - 3 + 2
<=> 0 = 2 (Vô lí)
Vậy nghiệm của PT là S = \(\varnothing\)
b: Ta có: \(\left(x-1\right)\left(x^2+1\right)-\left(x+1\right)\left(x^2-x+1\right)=x\left(2-x\right)\)
\(\Leftrightarrow x^3+x-x^2-1-x^3-1=2x-x^2\)
\(\Leftrightarrow-x^2+x-2-2x+x^2=0\)
\(\Leftrightarrow-x=2\)
hay x=-2
a, (2+x/2-x - 4x^2/x^2-4 - 2-x/2+x):x^2-3x/2x^2-x^3
a, 2x-1/2x+1 :(2x-1+2-4x/2x+1)
b,(1/1-x -1) : (x- 1-2x/1-x +1)
c,(1/x + x-2/x^2 -4 -2+x/x^2+2x):(x^2+2x+1)/x^2
d,{1/x^2 + 1/y^2 + 2/ x+y.(1/x + 1/y )} : x^3+y^3/x^2+y^2
đề là thực hiện phép tính
a: \(=\left(\dfrac{-\left(x+2\right)}{x-2}-\dfrac{4x^2}{\left(x-2\right)\left(x+2\right)}+\dfrac{x-2}{x+2}\right)\cdot\dfrac{2x^2-x^3}{x^2-3x}\)
\(=\dfrac{-x^2-4x-4-4x^2+x^2-4x+4}{\left(x-2\right)\left(x+2\right)}\cdot\dfrac{x^2\left(2-x\right)}{x\left(x-3\right)}\)
\(=\dfrac{-4x^2-8x}{x+2}\cdot\dfrac{-x}{x-3}\)
\(=\dfrac{-4x\left(x+2\right)}{x+2}\cdot\dfrac{-x}{x-3}=\dfrac{4x^2}{x-3}\)
b: \(=\dfrac{2x-1}{2x+1}:\left(2x-1+\dfrac{2-4x}{2x+1}\right)\)
\(=\dfrac{2x-1}{2x+1}:\dfrac{4x^2-1+2-4x}{2x+1}\)
\(=\dfrac{2x-1}{4x^2-4x+1}=\dfrac{1}{2x-1}\)
c: \(=\left(\dfrac{1}{1-x}-1\right):\left(x+1-\dfrac{2x-1}{x-1}\right)\)
\(=\dfrac{1-1+x}{1-x}:\dfrac{x^2-1-2x+1}{x-1}\)
\(=\dfrac{-x}{x-1}\cdot\dfrac{x-1}{x\left(x-2\right)}=\dfrac{-1}{x-2}\)
1) \(\dfrac{1}{x^2+6x+9}+\dfrac{1}{6x-x^2+9}+\dfrac{x}{x^2-9}\) 2) \(\dfrac{x^2+2}{x^3-1}+\dfrac{2}{x^2+x+1}+\dfrac{1}{1-x}\) 3) \(\dfrac{x-3}{x+1}-\dfrac{x+2}{x-1}+\dfrac{8x}{x^2-1}\)
Giải phương trình:
A) 1-x/x+1 +3 = 2x+3/x+1
B) (x+2)^2/2x-3 -1 = x^2-10/2x-3
C) 5x-2/2-2x + 2x-1/2 = 1 + x^2+x-3/x-1
D) 5-2x/3 - (x-1)(x+1)/1-3x = (x+2)(1-3x)/9x-3
E) x-3/x-2 + x-2/x-4 = -1
F) 1 + x/3-x = 5/(x+2)(3-x) + 2/x+2
G) x+1/x-1 - x-1/x+1 = 3x( 1 - x-1/x+1 )
H) 1-6x/x-2 + 9x-4/x+2 = x(3x-2)+1/x^2-4
I) 3x-1/x-1 - 2x+5/x+3 + 4/x^2+2x-3 = 1
\(\frac{1-x}{1+x}+3=\frac{2x+3}{x+1}\left(ĐKXĐ:x\ne-1\right)\)
\(\Leftrightarrow\frac{1-x}{x+1}+\frac{3\left(x+1\right)}{x+1}=\frac{2x+3}{x+1}\)
\(\Leftrightarrow\frac{1-x+3\left(x+1\right)}{x+1}=\frac{2x+3}{x+1}\)
\(\Rightarrow1-x+3\left(x+1\right)=2x+3\)
\(\Leftrightarrow1-x+3x+3=2x+3\)
\(\Leftrightarrow2x+4=2x+3\)
\(\Leftrightarrow0x=-1\)(vô nghiệm)
Vậy phương trình vô nghiệm.
\(\frac{\left(x+2\right)^2}{2x-3}-1=\frac{x^2-10}{2x-3}\left(ĐKXĐ:x\ne\frac{3}{2}\right)\)
\(\Leftrightarrow\frac{x^2+4x+4}{2x-3}-\frac{2x-3}{2x-3}=\frac{x^2-10}{2x-3}\)
\(\Leftrightarrow\frac{x^2+4x+4-2x+3}{2x-3}=\frac{x^2-10}{2x-3}\)
\(\Rightarrow x^2+4x+4-2x+3=x^2-10\)
\(\Leftrightarrow2x+7=-10\)
\(\Leftrightarrow2x=-17\)
\(\Leftrightarrow x=\frac{-17}{2}\)(thỏa mãn ĐKXĐ)
Vậy phương trình có nghiệm duy nhất : \(x=\frac{-17}{2}\)
Trả lời:
a, \(\frac{1-x}{x+1}+3=\frac{2x+3}{x+1}\)\(\left(đkxđ:x\ne-1\right)\)
\(\Leftrightarrow\frac{1-x+3\left(x+1\right)}{x+1}=\frac{2x+3}{x+1}\)
\(\Rightarrow1-x+3x+3=2x+3\)
\(\Leftrightarrow4+2x=2x+3\)
\(\Leftrightarrow2x-2x=3-4\)
\(\Leftrightarrow0x=-1\)(không thỏa mãn)
Vậy \(S=\varnothing\)
b, \(\frac{\left(x+2\right)^2}{2x-3}-1=\frac{x^2-10}{2x-3}\)\(\left(đkxđ:x\ne\frac{3}{2}\right)\)
\(\Leftrightarrow\frac{\left(x+2\right)^2-\left(2x-3\right)}{2x-3}=\frac{x^2-10}{2x-3}\)
\(\Rightarrow x^2+4x+4-2x+3=x^2-10\)
\(\Leftrightarrow x^2+2x+7=x^2-10\)
\(\Leftrightarrow x^2+2x-x^2=-10-7\)
\(\Leftrightarrow2x=-17\)
\(\Leftrightarrow x=\frac{-17}{2}\)(tm)
Vậy \(S=\left\{\frac{-17}{2}\right\}\)
c, \(\frac{5x-2}{2-2x}+\frac{2x-1}{2}=1+\frac{x^2+x-3}{x-1}\)\(\left(đkxđ:x\ne1\right)\)
\(\Leftrightarrow\frac{2-5x}{2x-2}+\frac{2x-1}{2}=1+\frac{x^2+x-3}{x-1}\)
\(\Leftrightarrow\frac{2-5x}{2\left(x-1\right)}+\frac{2x-1}{2}=1+\frac{x^2+x-3}{x-1}\)
\(\Leftrightarrow\frac{2-5x}{2\left(x-1\right)}+\frac{\left(2x-1\right)\left(x-1\right)}{2\left(x-1\right)}=\frac{2\left(x-1\right)}{2\left(x-1\right)}+\frac{2\left(x^2+x-3\right)}{2\left(x-1\right)}\)
\(\Rightarrow2-5x+2x^2-3x+1=2x-2+2x^2+2x-6\)
\(\Leftrightarrow2x^2-8x+3=2x^2+4x-8\)
\(\Leftrightarrow2x^2-8x-2x^2-4x=-8-3\)
\(\Leftrightarrow-12x=-13\)
\(\Leftrightarrow x=\frac{13}{12}\)(tm)
Vậy \(S=\left\{\frac{13}{12}\right\}\)