What is the solutions of the quadratic equation?

x2 = 9x + 6

Hello : 
note : 
the discriminat of each quadratic equation : ax²+bx+c=0 (a ≠ 0) is :
Δ = b² -4ac
1 )  Δ > 0  the equation has two reals solutions : x =  (-b±√Δ)/2a
2 ) Δ = 0 : one solution : x = -b/2a
3 ) Δ < 0 : no reals solutions
in this exercice : 
x² = 9x+6
x² -9x -6 = 0
Δ = b² - 4ac    ... a =1      b = -9   c  =-6
Δ = (-9)² -4(1)(-6)=105
He continued...