Question

tìm x hằng đẳng thức x^2 +4x +4=0

Answer 1

=x^2 +2.x.2 +2^2

=(x+2)^2

Answer 2

`x^2+4x+4=0`

`⇔x^2+2.x.2+2^2=0`

`⇔(x+2)^2=0`

`⇔x+2=0⇔x=−2`

Vậy `x=-2`.

Answer 3

\(x^2+4x+4=x^2+2.2.x+2^2=\left(x+2\right)^2=0\Rightarrow x+2=0\Rightarrow x=-2\)