Question 996998
{{{sqrt(x+15)-x=3}}} I should start by adding x to both sides so the equation now looks like this: {{{sqrt(x+15)=3+x}}} at this time, I square both sides to look like this: {{{sqrt(x+15)^2=(x+3)^2}}}
 Since the squares eliminate themselves on the left, I foil the right so the equation looks like this:
x+15=x^2+6x+9.
don't stop here, combine like terms on the right
0 = x^2 + 6x - x + 15 - 9
0 = x^2 + 5x - 6 
factors to 
(x+6)(x-1) = 0
positive solution
x = 1 is the solution
and
x = -6, will not be a solution in the original equation