Question 460093


{{{3(x+9)^2-81=0}}} Start with the given equation.



{{{3(x+9)^2=0+81}}}Add {{{81}}} to both sides.



{{{3(x+9)^2=81}}} Combine like terms.



{{{(x+9)^2=(81)/(3)}}} Divide both sides by {{{3}}}.



{{{(x+9)^2=27}}} Reduce.



{{{x+9=""+-sqrt(27)}}} Take the square root of both sides.



{{{x+9=sqrt(27)}}} or {{{x+9=-sqrt(27)}}} Break up the "plus/minus" to form two equations.



{{{x+9=3*sqrt(3)}}} or {{{x+9=-3*sqrt(3)}}}  Simplify the square root.



{{{x=-9+3*sqrt(3)}}} or {{{x=-9-3*sqrt(3)}}} Subtract {{{9}}} from both sides.



--------------------------------------



Answer:



So the solutions are {{{x=-9+3*sqrt(3)}}} or {{{x=-9-3*sqrt(3)}}}.