Question

If `x = -1/2` is a solution of the quadratic equation 3x² + 2kx – 3 = 0, then the value of k is ______.

Options

• `-3/4`

• `-5/4`

• `-9/4`

• `-4/5`

Answer 1

If `x = -1/2` is a solution of the quadratic equation 3x² + 2kx – 3 = 0, then the value of k is `underlinebb(-9/4)`.

Explanation:

Given,

`x = -1/2`

Equation: 3x² + 2kx – 3 = 0

Substituting value of x in equation:

⇒ 3x² + 2kx – 3 = 0

⇒ `3((-1)/2)^2 + 2k((-1)/2) - 3 = 0` 

⇒ `3(1/4) - k - 3 = 0` 

⇒ `(3/4) - k = 3` 

⇒ `k = 3/4 - 3`

⇒ `k = (3 - 12)/4` 

⇒ `k = -9/4`