(x+2)^2
This can be rewritten as:
(x + 2)(x + 2)
Multiply everything in the second parenthesis by x.
x^2 + 2x
Multiply everything in the second parenthesis by 2.
2x + 4
Add these equations together.
x^2 + 2x + 2x + 4
Combine like terms.
x^2 + 4x + 4
Hope this helps!