In (3x + 2)(x - 4), the coefficient of x is :

1. -14

2. 8

3. -10

4. 3

(x + y - z)(x - y + z) is equal to :

1. x² - y² - z² - 2yz

2. x² - y² - z² + 2yz

3. x² - y² + z² - 2yz

4. x² - y² + z² + 2yz

If x + 2y + 3z = 0 and x³ + 4y³ + 9z³ = 18xyz; evaluate :

$\dfrac{(x + 2y)^2}{xy} + \dfrac{(2y + 3z)^2}{yz} + \dfrac{(3z + x)^2}{zx}$

If $a + \dfrac{1}{a} = m$ and a ≠ 0; find in terms of 'm'; the value of :

(i) $a - \dfrac{1}{a}$

(ii) $a^2 - \dfrac{1}{a^2}$