Question

\\((x + 4y)(x + 4y)\\)

Explanation:

Apply the FOIL method

$$ (x + 4y)(x + 4y) = x \cdot x + x \cdot 4y + 4y \cdot x + 4y \cdot 4y $$

Simplify individual terms

$$ x^2 + 4xy + 4xy + 16y^2 $$

Combine like terms

$$ x^2 + 8xy + 16y^2 $$

Answer:

\(x^2 + 8xy + 16y^2\)