Find the product of all positive integer values of c such that 8x^2 + 45x + c = 0 has two real roots.
You can find all of them by making the discriminant positive:
b2 - 4·a·c >= 0 with a = 8 and b = 45
and solving for c.
Or, you can realize that one of the possible correct answers is 0; making the
product of all of them also 0.
