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PT \(\Leftrightarrow\frac{\left(x+3\right)\left(x-2\right)}{\left(x-4\right)\left(x-2\right)}+\frac{\left(x-1\right)\left(x-4\right)}{\left(x-4\right)\left(x-2\right)}=\frac{2}{-\left(x-4\right)\left(x-2\right)}\)

\(\Leftrightarrow\frac{-\left(x+3\right)\left(x-2\right)-\left(x-1\right)\left(x-4\right)}{-\left(x-4\right)\left(x-2\right)}=\frac{2}{-\left(x-4\right)\left(x-2\right)}\)

\(\Rightarrow-\left(x^2-2x+3x-6\right)-\left(x^2-4x-x+4\right)=2\)

\(\Leftrightarrow-x^2-x+6-x^2+5x-4=2\)

\(\Leftrightarrow-2x^2+4x=0\Leftrightarrow-2x\left(x-2\right)=0\Leftrightarrow x=0;x=2\)

Vậy nghiệm của phương trình là x = 0 ; x = 2 

8 tháng 1 2017

\(\frac{x-1}{x^2-9x+20}+\frac{2x-2}{x^2-6x+8}+\frac{3x-3}{x^2-x-2}+\frac{4x-4}{x^2+6x+5}=0\)

\(\Leftrightarrow\frac{x-1}{\left(x-5\right)\left(x-4\right)}+\frac{2\left(x-1\right)}{\left(x-4\right)\left(x-2\right)}+\frac{3\left(x-1\right)}{\left(x-2\right)\left(x+1\right)}+\frac{4\left(x-1\right)}{\left(x+1\right)\left(x+5\right)}=0\)

\(\Leftrightarrow\left(x-1\right)\left(\frac{10}{x^2-25}\right)=0\)

\(\Leftrightarrow x-1=0\)

\(\Leftrightarrow x=1\)  

PS: Điều kiện xác đinh bạn tự làm nhé 

7 tháng 1 2017

từ đề\(\Leftrightarrow\frac{x-1}{x\left(x-4\right)-5\left(x-4\right)}+\frac{2x-2}{x\left(x-2\right)-4\left(x-2\right)}+\frac{3x-3}{x\left(x+1\right)-2\left(x+1\right)}+\frac{4x-4}{x\left(x+1\right)+5\left(x+5\right)}=0\)

\(\Leftrightarrow\left(x-1\right)\left(\frac{1}{\left(x-4\right)\left(x-5\right)}+\frac{2}{\left(x-2\right)\left(x-4\right)}+\frac{3}{\left(x-2\right)\left(x+1\right)}+\frac{4}{\left(x+1\right)\left(x+5\right)}=0\right)\)

\(\Leftrightarrow\left(x-1\right)\left(\frac{1}{x-4}-\frac{1}{x-5}+\frac{1}{x-2}-\frac{1}{x-4}+\frac{1}{x-2}-\frac{1}{x+1}+\frac{1}{x+1}-\frac{1}{x-5}\right)=0\)

\(\Leftrightarrow\left(x-1\right)\left(\frac{2}{x-2}-\frac{2}{x-5}\right)=0\)\(\frac{2}{x-2}-\frac{2}{x-5}\)luôn khác 0 nên x-1=0 nên x=1.

Điều kiện xác định : x khác 4,5,2,-1. Do đó x=1 thỏa mãn. Vậy x=1

9 tháng 2 2020

\(ĐKXĐ:x\ne3;x\ne5;x\ne4;x\ne6\)

\(\frac{x}{x-3}-\frac{x}{x-5}=\frac{x}{x-4}-\frac{x}{x-6}\)

\(\Rightarrow\frac{x}{x-3}-\frac{x}{x-5}-\frac{x}{x-4}+\frac{x}{x-6}=0\)

\(\Rightarrow x\left(\frac{1}{x-3}-\frac{1}{x-5}-\frac{1}{x-4}+\frac{1}{x-6}\right)=0\)

\(\Rightarrow\orbr{\begin{cases}x=0\left(tm\right)\\\frac{1}{x-3}-\frac{1}{x-5}-\frac{1}{x-4}+\frac{1}{x-6}=0\left(1\right)\end{cases}}\)

\(\left(1\right)\Rightarrow\frac{1}{x-3}+\frac{1}{x-6}=\frac{1}{x-5}+\frac{1}{x-4}\)

\(\Rightarrow\frac{2x-9}{\left(x-3\right)\left(x-6\right)}=\frac{2x-9}{\left(x-5\right)\left(x-4\right)}\)

\(\Rightarrow\orbr{\begin{cases}x=\frac{9}{2}\left(tm\right)\\\left(x-3\right)\left(x-6\right)=\left(x-5\right)\left(x-4\right)\left(2\right)\end{cases}}\)

\(\left(2\right)\Leftrightarrow x^2-9x+18=x^2-9x+20\)

\(\Leftrightarrow0=2\left(L\right)\)

Vậy pt có 2 nghiệm \(\left\{0;\frac{9}{2}\right\}\)

27 tháng 2 2020

\(\Leftrightarrow\frac{2}{\left(2-x\right)\left(x-4\right)}+\frac{x-1}{2-x}-\frac{x+3}{x-4}=0\)

\(\Leftrightarrow\frac{2+\left(x-1\right)\left(x-4\right)-\left(x+3\right)\left(2-x\right)}{\left(2-x\right)\left(x-4\right)}=0\)

\(\Rightarrow2x^2-4x=0\Leftrightarrow x\left(x-2\right)=0\Rightarrow\left[{}\begin{matrix}x=0\\x=2\end{matrix}\right.\)

4 tháng 4 2020

\(a,\frac{3}{x^2+x-2}-\frac{1}{x-1}=\frac{-7}{x+2}\left(x\ne1;x\ne-2\right)\)

\(\Leftrightarrow\frac{3}{x^2+x-2}-\frac{1}{x-1}+\frac{7}{x+2}=0\)

\(\Leftrightarrow\frac{3}{\left(x-1\right)\left(x+2\right)}-\frac{1\left(x+2\right)}{\left(x-1\right)\left(x+2\right)}+\frac{7\left(x-1\right)}{\left(x-1\right)\left(x+2\right)}=0\)

\(\Leftrightarrow\frac{3}{\left(x-1\right)\left(x+2\right)}-\frac{x+2}{\left(x-1\right)\left(x+2\right)}+\frac{7x-7}{\left(x-1\right)\left(x+2\right)}=0\)

\(\Leftrightarrow\frac{3-x-2+7x-7}{\left(x-1\right)\left(x+2\right)}=0\)

\(\Leftrightarrow\frac{6x-8}{\left(x-1\right)\left(x+2\right)}=0\)

=> 6x-8=0

<=> x=\(\frac{8}{6}=\frac{4}{3}\left(tmđk\right)\)

4 tháng 4 2020

b) ĐKXĐ: x khác 2; x khác 4

\(\frac{2}{-x^2+6x-8}-\frac{x-1}{x-2}=\frac{x+3}{x-4}\)

<=> \(\frac{2}{\left(x-2\right)\left(x-4\right)}+\frac{x-1}{x-2}=\frac{x+3}{x-4}\)

<=> 2(x - 2) + (x - 1)(x - 4)(x - 2) = (x + 3)(x - 2)(x - 2)

<=> x^3 - 7x^2 + 16x - 12 = -x^3 + x^2 + 8x - 12

<=> x^2 - 7x^2 + 16x - 12 + x^3 - x^2 + 8x - 12 = 0

<=> 2x^3 - 8x^2 + 8x = 0

<=> 2x(x - 2)(x - 2) = 0

<=> 2x = 0 hoặc x - 2 = 0

<=> x = 0 (tmđk) hoặc x = 2 (ktmđk)

=> x = 2

27 tháng 10 2019

a) Theo mình thì chỉ min thôi nhé!

\(A=\frac{8x^2-1}{4x^2+1}+1+11=\frac{12x^2}{4x^2+1}+11\ge11\)

b)Bạn rút gọn lại giùm mìn, lười quy đồng lắm:(

16 tháng 3 2020

\(ĐKXĐ:\hept{\begin{cases}x\ne2\\x\ne4\end{cases}}\)

\(\frac{x+3}{x-4}+\frac{x-1}{x-2}=\frac{2}{6x-8-x^2}\)

\(\Leftrightarrow\frac{x+3}{x-4}+\frac{x-1}{x-2}+\frac{2}{\left(x-2\right)\left(x-4\right)}=0\)

\(\Leftrightarrow\frac{\left(x+3\right)\left(x-2\right)+\left(x-1\right)\left(x-4\right)+2}{\left(x-2\right)\left(x-4\right)}=0\)

\(\Leftrightarrow x^2+x-6+x^2-5x+4+2=0\)

\(\Leftrightarrow2x^2-4x=0\)

\(\Leftrightarrow2x\left(x-2\right)=0\)

\(\Leftrightarrow\orbr{\begin{cases}x=0\\x-2=0\end{cases}}\)

\(\Leftrightarrow\orbr{\begin{cases}x=0\left(tm\right)\\x=2\left(ktm\right)\end{cases}}\)

Vậy tập nghiệm của phương trình là \(S=\left\{0\right\}\)