Question

If one of the zeroes of the quadratic polynomial (k – 1)x² + k x + 1 is – 3, then the value of k is ______.

Options

• `4/3`

• `(-4)/3`

• `2/3`

• `(-2)/3`

Answer 1

If one of the zeroes of the quadratic polynomial (k – 1)x² + k x + 1 is – 3, then the value of k is `4/3`.

Explanation:

– 3 is one of the zeros of quadratic polynomial (k – 1)x² + kx + 1

Substituting – 3 in the given polynomial,

(k – 1)(– 3)² + k(– 3) + 1 = 0

(k – 1)9 + k(– 3) + 1 = 0

9k – 9 – 3k + 1 = 0

6k – 8 = 0

k = `8/6`

Therefore, k = `4/3`