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 the quadratic equation, ax² + bx + c = 0, a ≠ 0 is greater than zero and a perfect square and a, b, c are rational, then the roots are:

1. rational and equal

2. irrational and unequal

3. irrational and equal

4. rational and unequal

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

Which of the following is a quadratic equation?

1. x² + 1 = (2 - x)² + 3

2. 2x² + 3 = (5 + x)(2x - 3)

3. x³ - x² = (x - 1)³

4. none of these