[tex]x^2+8x=5[/tex]
[tex]x^2+8x + ( \frac{8}{2} )^2 =5 + (\frac{8}{2} )^2[/tex]
[tex]x^2+8x + (4)^2 =5 + (4)^2[/tex]
[tex](x+ 4)^2 =21[/tex]
[tex]x+ 4 = \pm \sqrt{21} [/tex]
[tex]x = \sqrt{21} - 4 \ or \ x= -\sqrt{21} - 4[/tex]
[tex]x = 0.58 \ or \ x= -8.58[/tex]
