Question 51610
Doing it the easy way:  Let's take the square root of both sides:  {{{sqrt((x+3)^2)=sqrt(81)}}}, which simplifies to {{{x+3=9}}}.  Because we are squaring the (x+3) though, that means that we could have two solutions, one positive and one negative ({{{x+3=-9}}}.  Solving for the first equation,  subtract 3 from both sides:  {{{x+3-3=9-3}}}, which simplifies to {{{x=6}}}.  Now solve for the second equation:  {{{x+3-3=-9-3}}}, which simplifies to {{{x=-12}}}.  So there are two solutions for x:  6 and -12.  An alternative way of solving is by using the quadratic equation and discriminant.