Question

\(x^2+4x+4=\)

Answer 1

Answer 2

\(x^2\) + \(4x\) + \(4\) = \(x^2\) + \(2.2x\) + \(2^2\) = \(\left(x+2\right)^2\)

Vậy \(x^2\) + \(4x\) + \(4\)  = \(\left(x+2\right)^2\)

Answer 3

 \(x^2+4x+4\\ =x^2+2x+2x+4\\ =\left(x^2+2x\right)+\left(2x+4\right)\\ =x\left(x+2\right)+2\left(x+2\right)\\ =\left(x+2\right)\left(x+2\right)\\ =\left(x+2\right)^2\)