The roots of the quadratic equation px² - qx + r = 0 are real and equal if :

(a) p² = 4qr

(b) q² = 4pr

(c) –q² = 4pr

(d) p² > 4qr

If the roots of the quadratic equation, ax² + bx + c = 0, a ≠ 0 are real and equal, then each root is equal to:

1. $\dfrac{-a}{2b}$

2. $\dfrac{-b}{2a}$

3. $\dfrac{-2a}{b}$

4. $\dfrac{-c}{2a}$

If the discriminant of a quadratic equation, ax² + bx + c = 0, is greater than zero and a perfect square and b is irrational, then the roots are:

1. irrational and unequal

2. irrational and equal

3. rational and unequal

4. rational and equal

Which of the following is a quadratic equation?

1. x² - $2\sqrt{x}$ + 7 = 0

2. 2x² - 5x = (x - 1)²

3. $x - \dfrac{1}{x} = 2x^{2}$

4. x² + $\dfrac{1}{x^{2}}$ = 2