Răspuns :
(a+b)^2 = a^2 + 2ab + b^2
In problema ta a = 2x ; b = 1
=> (2x+1)^2 = (2x)^2 + 2.2x.1 + 1^2 = 4x^2 + 4x + 1
In problema ta a = 2x ; b = 1
=> (2x+1)^2 = (2x)^2 + 2.2x.1 + 1^2 = 4x^2 + 4x + 1