You can put this solution on YOUR website! set f(x) = 0 to get:
-(x+3)^2 + 5 = 0
multiply both sides of this equation by -1 to get:
(x+3)^2 - 5 = 0
add 5 to both sides of this equation to get:
(x+3)^2 = 5
take the square root of both sides of this equation to get:
x + 3 = +/- square root of (5).
subtract 3 from both sides of this equation to get:
x = - 3 +/- square root of (5).
a graph of your equation looks like this:
you can verify the solution is good by substituting -3 + sqrt(5) in the original equation.
you should get 0 as the answer.
same result should be obtained by substituting -3 - sqrt(5) in the original equation.