Hello,

No, what you got is just the equation from which you want to find the discriminant.

It's x²+kx²-2x+12kx+9k-9=0

which can be grouped this way :

(1+k)x²+x(12k-2)+(9k-9)=0

you know that the discriminant of ax²+bx+c is b²-4ac.

Here, a=1+k, b=12k-2, c=9k-9.

note that , that is to say

and you'll have to state the case for , that is to say