Answer:
25x² + 20x + 4
Step-by-step explanation:
(5x + 2)²
= (5x + 2)(5x + 2)
Each term in the second factor is multiplied by each term in the first factor, that is
5x(5x + 2) + 2(5x + 2) ← distribute both parenthesis
= 25x² + 10x + 10x + 4 ← collect like terms
= 25x² + 20x + 4