Hi,
I do not know if this helpful to you but:
Solving to y we have:
y=-x^2/p-a/p
Now if (-a/p) is not 1, there is still solution. Check for a=-15, p=11 (x=2, y=1).
If this is what you mean...
I am not sure what you are doing. The meaning of (-a/p) is not a fraction, it means this.
There exists an and that solve this equation if and only if if and only if if and only if , and this has a solution if and only if .