Question 427167
{{{x^2+7x=-12}}}
To complete the square, take 1/2 of the
coefficient of {{{x}}}, square it, and add
it to both sides
{{{ x^2 + 7x + (7/2)^2 = -12 + (7/2)^2 }}}
{{{ x^2 + 7x + 49/4 = -48/4 + 49/4 }}}
{{{ ( x + 7/2 )^2 = 1/4 }}}
take the square root of both side
{{{ x + 7/2 = 1/2 }}}
{{{ x = -3 }}}
and
{{{ x + 7/2 = -1/2 }}}
{{{ x = -4 }}}
----------
You can check by plugging in {{{-3}}} for {{{x}}}
and then {{{-4}}} for {{{x}}}