jawab 3

Soal :

$2x^{2}+8x+3=0$

Jawab :
$x^{2}+4x+\frac{3}{2}=0$
$x^{2}+4x+...=-\frac{3}{2}+...$
$x^{2}+4x+\left ( \frac{4}{2} \right )^{2}=-\frac{3}{2}+\left ( \frac{4}{2} \right )^{2}$
$x^{2}+4x+ ( 2 )^{2}=-\frac{3}{2}+4$
$\left ( x+2 \right )^{2}=\frac{5}{2}$
$x+2=\pm \sqrt{\frac{5}{2}}$
$x=-2+ \sqrt{\frac{5}{2}}\: \textrm{atau}\:x=-2- \sqrt{\frac{5}{2}}$