a: \(\dfrac{4x^4+3x^3}{-x^3}+\dfrac{15x^3+6x}{3x}=0\)
\(\Leftrightarrow-4x-3+5x^2+2=0\)
\(\Leftrightarrow5x^2-4x-1=0\)
\(\Leftrightarrow5x^2-5x+x-1=0\)
=>(x-1)(5x+1)=0
=>x=1 hoặc x=-1/5
b: \(\dfrac{x^2-\dfrac{1}{2}x}{2x}-\dfrac{\left(3x-1\right)^2}{3x-1}=0\)
\(\Leftrightarrow\dfrac{1}{2}x-\dfrac{1}{4}-3x+1=0\)
\(\Leftrightarrow\dfrac{-5}{2}x+\dfrac{3}{4}=0\)
\(\Leftrightarrow-\dfrac{5}{2}x=-\dfrac{3}{4}\)
hay \(x=\dfrac{3}{4}:\dfrac{5}{2}=\dfrac{3}{4}\cdot\dfrac{2}{5}=\dfrac{6}{20}=\dfrac{3}{10}\)