Question

If x − a is a factor of 2x³ − 2a²x + x − 5, then the value of ‘a’ is ______.

Options

• −1

• 1

• −5

• 5

Answer 1

If x − a is a factor of 2x³ − 2a²x + x − 5, then the value of ‘a’ is 5.

Explanation:

Let p(x) = 2x³ − 2a²x + x − 5

x − a is a factor of p(x),

p(a) = 0

⇒ 2(a)³ − 2a²(a) + (a) − 5 = 0

⇒ 2a³ − 2a³ + a − 5 = 0

⇒ a − 5 = 0

⇒ a = 5