If x = 3 is a root of the quadratic equation x² - 2kx - 6 = 0, then the value of k is :

1. 1

2. 2

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

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

If on dividing 4x² - 3kx + 3 by (x + 2), the remainder is k - 1, then the value of k is :

1. 4

2. -4

3. 3

4. -3

If A = $\begin{bmatrix$}[r] 3 & 4 \ 0 & 1 \end{bmatrix} \text{ and } B = \begin{bmatrix}[r] 9 & 16 \ 0 & -x \end{bmatrix} such that A² = B, then the value of x is :

1. 4

2. -1

3. 1

4. -4

If a - 1, a + 3, 3a - 1 are in A.P. then the value of a is :

1. 2

2. 4

3. -2

4. -4