How do is this problem worked? Find the difference quotient and simplfy answer.?

Question

g(x)=1/x^2, g(x)-g(3)/x-3, "x is not equal to 3"
Please list steps.

Answer 1

[g(x) - g(3)]/(x - 3) = (1/x^2 - 1/3^2)/(x - 3) =
(9 - x^2)/[9(x^2)*(x - 3)] = -(3 + x)/9(x^2).