10
QuizMultiple Choice

Multiplying Polynomials and Simplifying Expressions — Quiz

Question 10 • Algebra I

The polynomial x cubed plus 8 is equal to

Answer
A
open paren x plus 2 close paren times open paren x squared minus 2 x plus 4 close paren .
B
open paren x minus 2 close paren times open paren x squared plus 2 x plus 4 close paren.
C
open paren x minus 2 close paren times open paren x squared plus 2 x plus 8 close paren .
D
open paren x plus 2 close paren times open paren x squared minus 2 x plus 8 close paren .

Explanation

Use the sum-of-cubes rule: a³ + b³ = (a + b)(a² − ab + b²). Here, x³ + 8 = x³ + 2³, so it factors as (x + 2)(x² − 2x + 4). This matches choice C.

AI-written and checked against the verified answer.