\(1\text{)}\left(x-5\right)^2+3\left(x-5\right)=0\)
\(\Leftrightarrow\left(x-5\right)\left(x-5+3\right)=0\)
\(\Leftrightarrow\left(x-5\right)\left(x-2\right)=0\)
\(\Rightarrow\left[{}\begin{matrix}x=2\\x=5\end{matrix}\right.\)
\(2\text{)}\dfrac{2x-1}{3}-\dfrac{5x+2}{7}=x+13\)
\(\Leftrightarrow\dfrac{7\left(2x-1\right)-3\left(5x+2\right)}{21}=\dfrac{21\left(x+13\right)}{21}\)
\(\Leftrightarrow14x-7-15x-6=21x+273\)
\(\Leftrightarrow-x-13=21x+273\)
\(\Leftrightarrow-22x=286\)
\(\Rightarrow x=-\dfrac{286}{22}=-\dfrac{143}{11}\)
\(3\text{)}\dfrac{x-1}{x+2}-\dfrac{x}{x-2}=\dfrac{7x-6}{4-x^2}\left(đk:x\ne\pm2\right)\)
\(\Leftrightarrow\dfrac{x-1}{2+x}+\dfrac{x}{2-x}=\dfrac{7x-6}{4-x^2}\)
\(\Leftrightarrow\dfrac{\left(x-1\right)\left(2-x\right)+x\left(2+x\right)}{4-x^2}=\dfrac{7x-6}{4-x^2}\)
\(\Leftrightarrow2x-x^2-2+x+2x+x^2=7x-6\)
\(\Leftrightarrow x-2=7x-6\)
\(\Leftrightarrow-6x=-4\)
\(\Rightarrow x=\dfrac{2}{3}\)
1.(x−5)2+3(x−5)=0
=>(x-5)(x-5)+3.(x-5)=0
=>(x-5).(x-5+3)=0
=>x-5=0 hoặc x-2=0
=>x=5 hoặc x=2
2)\(\dfrac{2x-1}{3}\)-\(\dfrac{5x+2}{7}\)=x+13
=>\(\dfrac{7.\left(2x-1\right)}{7.3}\)-\(\dfrac{3.\left(5x+2\right)}{3.7}\)=\(\dfrac{21.\left(x+13\right)}{21}\)
=>khử mẫu:
=>7.(2x-1)-3.(5x+2)=21.(x+13)
=>14x-7-15x-6=21x+273
=>14-7-15x-6-21x-273=0
=>-36x-272=0
=>-36x=272
=>x=...
