[tex]x-3x^2=9\\\\3x^2-x=-9\ \ \ \ |:3\\\\x^2-\dfrac{1}{3}x=-3\\\\x^2-2\cdot x\cdot\dfrac{1}{6}+\left(\dfrac{1}{6}\right)^2=-3+\left(\dfrac{1}{6}\right)^2\ \ \ \ |use:\ (a-b)^2=a^2-2ab+b^2\\\\\left(x-\dfrac{1}{6}\right)^2=-3+\dfrac{1}{36}\\\\\left(x-\dfrac{1}{6}\right)^2=-2\dfrac{35}{36}[/tex]
Answer: No solution.