Algebra
# Polynomial Factoring

Which of the following must be a factor of

$x^3 + 8 ?$

Note: $a^3 + b^3 = ( a + b ) ( a^2 - ab + b^2 ) .$

Using the identity $a^2 - b^2 = (a-b) ( a+b)$, which of the following must be a factor of

$x^4 + 2500 ?$

**non-positive integers** such that the following is an algebraic identity in $x$: $(x-a)^2(x+a)^2=x^4+bx^3+cx^2+dx+256.$ What is the value of $-a-b-c-d$?

$x^4 - 81$?

Which of the following is a factor of