\[-6{x}^{2}=5x+9\]

1
Move all terms to one side.
6x2+5x+9=06{x}^{2}+5x+9=0

2
Use the Quadratic Formula.
x=5+191ı12,5191ı12x=\frac{-5+\sqrt{191}\imath }{12},\frac{-5-\sqrt{191}\imath }{12}

Done

How can we make this solution more helpful?