Tìm x biết rằng: 2x^2 +2x + 1/2 = 0

* Hướng dẫn giải

$\begin{array}{l}2x^2+2x+\frac{1}{2}=0\\ 2\left(x^2+x+\frac{1}{4}\right)=0\\ 2{\left(x+\frac{1}{2}\right)}^2=0\\ {\left(x+\frac{1}{2}\right)}^2=0\\ x=-\frac{1}{2}\end{array}$

Vậy $x=-\frac{1}{2}$