a) \(\dfrac{x-1}{x+5}=\dfrac{6}{7}\left(đk:x\ne-5\right)\)
\(\Rightarrow7\left(x-1\right)=6\left(x+5\right)\)
\(\Rightarrow x=37\left(tm\right)\)
b) \(\dfrac{x^2}{6}=\dfrac{24}{49}\)
\(\Rightarrow x^2=\dfrac{24.6}{49}=\dfrac{144}{49}\)
\(\Rightarrow\left[{}\begin{matrix}x=\dfrac{12}{7}\\x=-\dfrac{12}{7}\end{matrix}\right.\)