Answer:
x² + 2cx + c²
Step-by-step explanation:
(x + c)² = (x + c)(x + c)
Each term in the second factor is multiplied by each term in the first factor, that is
x(x + c) + c(x + c) ← distribute parenthesis
= x² + cx + cx + c² ← collect like terms
= x² + 2cx + c²
