Question 685133
{{{ x^3-3x^2-9x+27}}}.....group


{{{ (x^3-9x)-(3x^2-27)}}}...factor out

{{{ x(x^2-9)-3(x^2-9)}}}

{{{ (x-3)(x^2-9)}}}

{{{ (x-3)(x^2-3^2)}}}

{{{ (x-3)(x-3)(x+3)}}}

solutions:

if  {{{ x-3=0}}}..=>...{{{ x=3}}}....one double solution

if  {{{ x+3=0}}}..=>...{{{ x=-3}}}


{{{ graph( 600, 600, -10, 10, -10, 40,  x^3-3x^2-9x+27) }}}