Question

if X + a is the factor of the polynomial 2x square + 2a X + 5 x + 10 find the value of a

Answer 1

Let f(x) = 2x^2 + 2ax + 5x + 10
If (x+a) is a factor then by the factor theorem f(-a)=0
f(-a) = 2a^2 - 2a^2 - 5a +10 = 0
-5a + 10 = 0
a = 2

Hope this helps you