\(a,\left(x-5\right)^2+3\left(x-5\right)=0\\ \Leftrightarrow\left(x-5\right)\left(x-5+3\right)=0\\ \Leftrightarrow\left(x-5\right)\left(x-2\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x=5\\x=2\end{matrix}\right.\\ b,\dfrac{2x-1}{3}-\dfrac{5x+2}{7}=x+3\\ \Leftrightarrow\dfrac{7\left(2x-1\right)}{21}-\dfrac{3\left(5x+2\right)}{21}-\dfrac{21\left(x+3\right)}{21}=0\\ \Leftrightarrow14x-7-15x-6-21x-63=0\\ \Leftrightarrow-22x-76=0\\ \Leftrightarrow x=-\dfrac{38}{11}\)
c, ĐKXĐ:\(x\ne\pm2\)
\(\dfrac{x-1}{x+2}-\dfrac{x}{x-2}=\dfrac{7x-6}{4-x^2}\\ \Leftrightarrow\dfrac{\left(x-1\right)\left(x-2\right)}{\left(x-2\right)\left(x+2\right)}-\dfrac{x\left(x+2\right)}{\left(x-2\right)\left(x+2\right)}=\dfrac{-\left(7x-6\right)}{x^2-4}\\ \Leftrightarrow\dfrac{x^2-3x+2}{\left(x-2\right)\left(x+2\right)}-\dfrac{x^2+2x}{\left(x-2\right)\left(x+2\right)}+\dfrac{7x-6}{\left(x-2\right)\left(x+2\right)}=0\\ \Leftrightarrow\dfrac{x^2-3x+2-x^2-2x+7x-6}{\left(x-2\right)\left(x+2\right)}=0\\ \Rightarrow2x-4=0\\ \Leftrightarrow x=2\left(ktm\right)\)
a, \(\left(x-5\right)\left(x-2\right)=0\Leftrightarrow x=2;x=5\)
b, \(14x-7-15x-6=21x+63\Leftrightarrow-22x=76\Leftrightarrow x=-\dfrac{38}{11}\)
c, đk : x khác -2 ; 2
\(x^2-3x+2-x^2-2x=6-7x\Leftrightarrow x=4\left(tm\right)\)
\(a)\)\((x-5+3)(x-5)=0\Leftrightarrow (x-2)(x-5)=0\Leftrightarrow x=2,x=5\)
b)\(\dfrac{14x-7}{21}-\dfrac{15x+6}{21}=\dfrac{21x+63}{21}\Leftrightarrow 14x-7-15x-6-21x-63=0\Leftrightarrow -22x-76=0\Leftrightarrow x=-\dfrac{38}{11}\) c) ĐKXĐ x khác 2 và -2
\(\dfrac{x^{2}-3x+2}{(x-2)(x+2)}-\dfrac{x^{2}+2x}{(x-2)(x+2)}+\dfrac{7x-6}{(x-2)(x+2)}=0\)\(\Leftrightarrow 2x-4=0\Leftrightarrow x=2(loại)\)\(\Leftrightarrow \)PT Vô Nghiêm
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