Question 121387
{{{sqrt(9x+100)=x-10}}}
{{{9x+100=(x-10)^2}}}Square both sides.
{{{9x+100=x^2-20x+100}}} Expand the right hand side.
{{{0=x^2-29x}}} Subtract (9x+100) from both sides. 
{{{x(x-29)=0}}}
Two solutions:
{{{highlight(x=0)}}}
and
{{{x-29=0}}}
{{{highlight(x=29)}}}