Question 724739
{{{ x^2 = 9x + 20 }}}
Subtract {{{ 9x }}} from both sides
{{{ x^2 - 9x = 20 }}}
Complete the square. Take 1/2 of the {{{ -9 }}},
square it, and add it to both sides
{{{ x^2 - 9x + ( -9/2 )^2 = 20 + ( -9/2 )^2 }}}
{{{ x^2 - 9x + 20.25 = 20 + 20.25 }}}
{{{ ( x - 4.5 )^2 = 40.25 }}}
Take the square root of both sides
{{{ x - 4.5 = sqrt( 40.25 ) }}}
and
{{{ x - 4.5 = -sqrt( 40.25 ) }}}
The factors are
{{{  x - 4.5 + sqrt( 40.25 ) }}} and
{{{  x - 4.5 - sqrt( 40.25 ) }}}