a, ĐKXĐ:\(x\ne-3\)
\(\dfrac{x-2}{x+3}=\dfrac{5}{2}\\ \Rightarrow2\left(x-2\right)=5\left(x+3\right)\\ \Rightarrow2x-4=5x+15\\ \Rightarrow5x+15-2x+4=0\\ \Rightarrow3x+19=0\\ \Rightarrow x=-\dfrac{19}{3}\)
b, ĐKXĐ:\(x\ne1\)
\(\dfrac{4x-1}{x-1}=\dfrac{7}{2}\\ \Rightarrow2\left(4x-1\right)=7\left(x-1\right)\\ \Rightarrow8x-2=7x-7\\ \Rightarrow8x-2-7x+7=0\\ \Rightarrow x+5=0\\ \Rightarrow x=-5\)
c, ĐKXĐ:\(\left\{{}\begin{matrix}x\ne3\\x\ne-2\end{matrix}\right.\)
\(\dfrac{4}{x-3}=\dfrac{5}{x+2}\\ \Leftrightarrow4\left(x+2\right)=5\left(x-3\right)\\ \Leftrightarrow4x+8=5x-15\\ \Leftrightarrow5x-15-4x-8=0\\ \Leftrightarrow x-23=0\\ \Leftrightarrow x=23\)
d, ĐKXĐ:\(x\ne-3\)
\(\dfrac{x-6}{x+3}=\dfrac{7}{4}\\ \Leftrightarrow4\left(x-6\right)=7\left(x+3\right)\\ \Leftrightarrow4x-24=7x+21\\ \Leftrightarrow7x+21-4x+24=0\\ \Leftrightarrow3x+45=0\\ \Leftrightarrow x=-15\)
