NCERT Exemplar Solutions
Class 10 - Mathematics - CHAPTER 2: Polynomials - Exercise 2.1
Question 1

Question.  1

If one of the zeroes of the quadratic polynomial \((k-1)x^2 + kx + 1\) is \(-3\), then the value of k is

(A)

\(\dfrac{4}{3}\)

(B)

\(-\dfrac{4}{3}\)

(C)

\(\dfrac{2}{3}\)

(D)

\(-\dfrac{2}{3}\)

Detailed Answer with Explanation:

Step 1: Recall the condition.

If \(-3\) is a zero of the polynomial \((k-1)x^2 + kx + 1\), then by definition:

\((k-1)(-3)^2 + k(-3) + 1 = 0\).

Step 2: Simplify the expression.

\((k-1)(9) - 3k + 1 = 0\)

\(9k - 9 - 3k + 1 = 0\)

Step 3: Combine like terms.

\(9k - 3k = 6k\)

\(-9 + 1 = -8\)

So the equation becomes \(6k - 8 = 0\).

Step 4: Solve for \(k\).

\(6k = 8\)

\(k = \dfrac{8}{6}\)

\(k = \dfrac{4}{3}\)

Final Answer: The required value of \(k\) is \(\dfrac{4}{3}\).

NCERT Exemplar Solutions Class 10 – Mathematics – CHAPTER 2: Polynomials – Exercise 2.1 | Detailed Answers