How do you find the discriminant and how many solutions does #7c^2 + 8c + 1 = 0# have?
There is another way.
No need to solve this type of quadratic equation. Use shortcut.
Since a - b + c = 0, there are 2 real roots: (-1) and (-c/a = -1/7).
Reminder of shortcut:
a. When a + b + c = 0, one real root is (1) and the other is (c/a).
b. When a - b + c = 0, one real root is (-1) and the other is (-c/a).