# If $x+1$ is a factor of $ax^4 + bx^2 + c,$ what is the value of $a + b + c?$ [duplicate]

The same question was posed here Find the value of a+b+c but I cannot make sense of the answer.

My long division must be incorrect as I ended up with $a+b+c$ which is definitely wrong. I added $0$ to represent $x^3$ and $x^1$ terms.

I know the remainder should be zero if $x+1$ is a factor.

I am not putting two and two together.

• If $x+1$ is a factor then $x=-1$ is a root. @user554754 can you finish? – Minz Apr 26 '18 at 3:30