when you use all prime, non-one numbers for b and c, it cannot be factored most of the time
example
1x^2+7x+5
a=1
b=7
c=5
x=
x=
x=
x=
x=
or 
example
1x^2+7x+5
a=1
b=7
c=5
x=
x=
x=
x=
x=
4.125... rational or irrational
2 answers:
You might be interested in
First note that 
; otherwise 
is undefined as long as we're only looking for real solutions.
We can write
We can write