The roots of the quadratic equation 2x² - x - 6 = 0 are:

1. -2, $\dfrac{3}{2}$

2. 2, $\dfrac{-3}{2}$

3. -2, $\dfrac{-3}{2}$

4. 2, $\dfrac{3}{2}$

Which of the following quadratic equations has 2 and 3 as its roots?

1. x² - 5x + 6 = 0

2. x² + 5x + 6 = 0

3. x² - 5x - 6 = 0

4. x² + 5x - 6 = 0

If x = $\dfrac{-1}{2}$ is a solution of the quadratic equation 3x² + 2kx - 3 = 0, then the value of k is:

1. $-\dfrac{3}{4}$

2. $-\dfrac{5}{4}$

3. $-\dfrac{9}{4}$

4. $-\dfrac{4}{5}$

If ax² + bx + c = 0 has equal roots, then c = ?

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

2. $\dfrac{b^{2}}{4a}$

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

4. $-\dfrac{b^{2}}{4a}$