Question

Factor 2k^2 - k - 3

A: (2k-3)(k+1)
B: (k-1)(2k+3)
C: (2k-1)(k+3)
D: (k-3)(2k+1)

Answer 1

A

Explanation:

Given

2k² - k - 3

Consider the factors of the product of the k² term and the constant term which sum to give the coefficient of the k- term.

product = 2 × - 3 = - 6 and sum = - 1

The factors are + 2 and - 3

Use these factors to split the k- term

2k² + 2k - 3k - 3 ( factor the first/second and third/fourth terms )

= 2k(k + 1) - 3(k + 1) ← factor out (k + 1) from each term

= (2k - 3)(k + 1) → A