Answer :
x(x+2) = 99
x^2 + 2x -99 = 0
(x+11)(x-9) = 0
x = -11 or x = 9
-11 and -9 or 9 and 11. Both sets work
x^2 + 2x -99 = 0
(x+11)(x-9) = 0
x = -11 or x = 9
-11 and -9 or 9 and 11. Both sets work