Answer:
a³ + 3a²x + 3ax² + x³
Explanation:
(a + x)³
= (a + x)(a + x)(a + x) ← expand the last 2 factors using FOIL
= (a + x)(a² + 2ax + x²)
Each term in the second factor is multiplied by each term in the first factor
= a(a² + 2ax + x²) + x(a² + 2ax + x²) ← distribute parenthesis
= a³ + 2a²x + ax² + a²x + 2ax² + x³ ← collect like terms
= a³ + 3a²x + 3ax² + x³