Question

If (x + a) is a factor of (2x² + 2ax + 5x + 10), then find the value of a.

Answer 1

Given: (x + a) is a factor of 2x² + 2ax + 5x + 10

We have 

x + a = 0

⇒ x = –a 

Since, (x + a) is a factor of 2x² + 2ax + 5x + 10

Hence, It will satisfy the above polynomial

∴ 2(–a)² + 2a(–a) + 5(–a) + 10 = 0

⇒ –5a + 10 = 0

⇒ a = 2