\(\left(2x^2-3x+1\right)\left(2x^2+5x+1\right)=9x^2\)
\(\Leftrightarrow4x^4+4x^3+2x+1=20x^2\)
\(\Leftrightarrow4x^4+4x^3-20x^2+2x+1=0\)
\(\Leftrightarrow\left(x-1\right)\left(2x-1\right)\left(x\left(2x+5\right)+1\right)=9x^2\)
\(\Leftrightarrow4x^4+4x^3-11x^2+2x+1=9x^2\)
\(\Leftrightarrow x=1-\frac{1}{\sqrt{2}}\)
\(\Leftrightarrow x=1+\frac{1}{\sqrt{2}}\)
\(\Leftrightarrow x=-\frac{3}{7}-\frac{\sqrt{7}}{2}\)
\(\Rightarrow x=\frac{\sqrt{7}}{2}=-\frac{3}{2}\)
\(\left(2x^2-3x+1\right)\left(2x^2+5x+1\right)=9x^2\)
\(\Leftrightarrow4x^4+4x^3+2x+1=20x^2\)
\(\Leftrightarrow4x^4+4x^3+2x+1=0\)
\(\Leftrightarrow\left(x-1\right)\left(2x-1\right)\left(2\left(2x+5\right)+1\right)=9x^2\)
