Describe the difference between an underestimate and an overestimate

If a is a nonzero real number then the reciprocal of a is

Subtract and simplify. (-y^2 – 4y - 8) – (-4y^2 – 6y + 3) show how you got the answer if your answer is right i will mark you

What is the value of the discriminant, b2 ? 4ac, for the quadratic equation 0 = x2 ? 4x + 5, and what does it mean about the number of real solutions the equation has?