Answer:
b = -5
Step-by-step explanation:
You needy to calculate the Discriminant = b² - 4ac
If D is zero there is one real solution,
If D less then zero there are no real solutions
Only if D is bigger then zero, there are two real solutions.
x² - 5x + 5 D > 0 so 2 real solutions
see attachment.
x² - 3x + 5 D < 0 so no real solutions
x² + 3x + 5 D < 0 so no real solutions
x² + 4x + 5 D < 0 so no real solutions
