Question 523319
{{{   x^2 + 8x   + 16 = 9 }}}
{{{   x^2 + 8x   + 4^2 = 9 }}}
{{{ (  x + 4  )^2 = 9 }}}
{{{ (  x + 4  )^2 = (3)^2 }}}
{{{ sqrt((  x + 4  )^2) = sqrt((3)^2 )}}}
{{{ x + 4 = 3}}}
{{{ x = 3-4}}}
{{{ x = -1}}}
Or
{{{ x + 4 = -3}}}
{{{ x + 4 = -3-4}}}
{{{ x + 4 = -7}}}

x= -7, -1