\(a,6\left(x-3\right)+x-1=0\\ \Leftrightarrow6x-18+x-1=0\\ \Leftrightarrow7x-19=0\\ \Leftrightarrow x=\dfrac{19}{7}\\ b,4x^2-1=\left(x+3\right)\left(2x+1\right)\\ \Leftrightarrow\left(2x+1\right)\left(2x-1\right)-\left(x+3\right)\left(2x+1\right)=0\\ \Leftrightarrow\left(2x+1\right)\left(2x-1-x-3\right)=0\\ \Leftrightarrow\left(2x+1\right)\left(x-4\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x=-\dfrac{1}{2}\\x=4\end{matrix}\right.\)
c, ĐKXĐ:\(x\ne2,x\ne-3\)
\(\dfrac{7}{x+3}-\dfrac{4}{x-2}=\dfrac{x-3}{\left(x+3\right)\left(x-2\right)}\\ \Leftrightarrow\dfrac{7\left(x-2\right)}{\left(x+3\right)\left(x-2\right)}-\dfrac{4\left(x+3\right)}{\left(x+3\right)\left(x-2\right)}-\dfrac{x-3}{\left(x+3\right)\left(x-2\right)}=0\\ \Leftrightarrow\dfrac{7x-14-4x-12-x+3}{\left(x+3\right)\left(x-2\right)}=0\\ \Rightarrow2x-23=0\\ \Leftrightarrow x=\dfrac{23}{2}\left(tm\right)\)
