Question

Find the value of 'k' so that x - 2 is a factor of:

x² + x - k

a. -3
b. 2
c. 4
d. 6

Answer 1

k = 6

Explanation:

If (x - 2) is a factor of f(x) then f(2) = 0

f(x) = x² + x - k , then

2² + 2 - k = 0

4 + 2 - k = 0

6 - k = 0 ( subtract 6 from both sides )

- k = - 6 ( multiply both sides by - 1 )

k = 6