If x + 2a is a factor of a5 -4a2x3 +2x + 2a +3,

Let p(x) =a5 -4a2x3 +2x + 2a +3

Since, x + 2a is a factor of p(x), then put p(-2a) = 0 (-2a)5 – 4a2 (-2a)3 + 2(-2a) + 2a + 3 = 0 => -32a5 + 32a5 -4a + 2a+ 3 = 0

=> -2a + 3=0

2a =3

a = 3/2.

Hence, the value of a is 3/2.