4) \(\left(2x+1\right)\left(4x^2-2x+1\right)-8x\left(x^2+2\right)=17\)
\(\Leftrightarrow8x^3+1-8x^3-16x=17\)
\(\Leftrightarrow-16x=16\)
\(\Leftrightarrow x=-1\)
-Vậy \(S=\left\{-1\right\}\)
5) \(\left(x-3\right)\left(2x-2\right)-\left(2x+3\right)\left(x-5\right)+3x=11\)
\(\Leftrightarrow2x^2-8x+6-\left(2x^2-7x-15\right)+3x=11\)
\(\Leftrightarrow2x^2-8x+6-2x^2+7x+15+3x=11\)
\(\Leftrightarrow2x+21=11\)
\(\Leftrightarrow2x=-10\)
\(\Leftrightarrow x=-5\)
-Vậy \(S=\left\{-5\right\}\)
6) \(\left(3x+1\right)\left(9x^2-3x+1\right)-3x^2\left(9x+1\right)+x\left(3x-2\right)-1=10\)
\(\Leftrightarrow27x^3+1-27x^3-3x^2+3x^2-2x-1=10\)
\(\Leftrightarrow-2x=10\)
\(\Leftrightarrow x=-5\)
-Vậy \(S=\left\{-5\right\}\)
