100
Coefficients are a=5, b=6, c=1
Quadratic Formula: x=
−b±√b2−4ac
2a
Put in a, b and c: x=
−6±√64−4*5*1
2*5
x=
−6±√(36−20)
10
x=
−6±√(16)
10
x=
−6±4
10
x=−0.2 or −1
Do you see b2−4ac in the formula above? It is called the Discriminant, because it can "discriminate" between the possible types of answer:
When b2−4ac is positive, you get two Real solutions
When it is zero you get just ONE real solution (both answers are the same)
When it is negative you get two Complex solutions