Question 714619
{{{ sqrt(12x^3) + sqrt(9x^3) - sqrt(81x^3) }}}
Factor to reveal the perfect squares inside the radicals
{{{ sqrt(4*3*x^2*x) + sqrt(9x^2*x) - sqrt(81x^2*x) }}}
Extract those perfect square
{{{ 2x*sqrt(3x) + 3x*sqrt(x) - 9x*sqrt(x) }}}
Combine the like terms
{{{ 2x*sqrt(3x)}}} - {{{6x*sqrt(x) }}}