Factor the #x^2+6x+9# and then take the square root of the entire equation. Then simply get x alone and you'll have your answers. #x=2 and -8#
Explanation:
1: #x^2+6x+9# can be factored as #(x+3)*(x+3)# or #(x+3)^2#
2: #(x+3)^2= 25# take square root of entire equation
3: #x+3 = +-5#
4: #x= 5-3# and #x=-5-3#
Thus #x = 2# and #-8#