Question

If x+5 is a factor of 2x^3-4x^2+ax+5, then value of a is

Answer 1

the remainder when f(x) is divided by (x+5) is f(-5) = -5a-345
so, since x+5 is a factor, that means that
-5a-345=0
a = -69
check:
2x^3 - 4x^2 - 69x + 5 = (x+5)(2x^2 - 14x + 1)

Answer 2

Tatakae