c: Ta có: \(\left(3x-5\right)^2-x\left(3x-5\right)=0\)
\(\Leftrightarrow\left(3x-5\right)\left(2x-5\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{5}{3}\\x=\dfrac{5}{2}\end{matrix}\right.\)
d: Ta có: \(\left(x+2\right)\left(x^2-2x+4\right)-x\left(x^2-2\right)=15\)
\(\Leftrightarrow x^3+8-x^3+2x=15\)
\(\Leftrightarrow2x=7\)
hay \(x=\dfrac{7}{2}\)
e: Ta có: \(\left(2x+1\right)\left(4x^2-2x+1\right)-8x\left(x^2+2\right)=x^2-16\)
\(\Leftrightarrow8x^3+1-8x^3-16x-x^2+16=0\)
\(\Leftrightarrow-x^2-16x+17=0\)
\(\Leftrightarrow x^2+16x-17=0\)
\(\Leftrightarrow\left(x+17\right)\left(x-1\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=-17\\x=1\end{matrix}\right.\)
