You can put this solution on YOUR website! (x^2 - 6x + 9) / (x^2 - 9)
factor
=(x-3)(x-3)/(x-3)(x+3)
FYI a^2 - b^2 = (a+b)(a-b)
cancel out (x-3)
=(x-3)/(x+3) I think that is fully simplified. You might also have to say that x can not equal positive or negative 3.