a) Ta có: \(\left(2x+1\right)^2-\left(3x-4\right)^2=0\)
\(\Leftrightarrow\left(2x+1-3x+4\right)\left(2x+1+3x-4\right)=0\)
\(\Leftrightarrow\left(5-x\right)\left(5x-3\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=5\\x=\dfrac{3}{5}\end{matrix}\right.\)
b) Ta có: \(5x^3-3x^2+10x-6=0\)
\(\Leftrightarrow x^2\left(5x-3\right)+2\left(5x-3\right)=0\)
\(\Leftrightarrow5x-3=0\)
hay \(x=\dfrac{3}{5}\)