I need help.

6/x-3 + 2x/x^2-9 = 1/x+3

I am going to assume that you meant ...

6/(x-3) + 2x/(x^2-9) = 1/(x+3)

did you notice that x^2 - 9 = (x+3)(x-3) ?

so multiply each term by x^2-9

6(x+3) + 2x = 1(x-3)

take it from there.