ask ko lang po kung panong gagawin ko sa equation na to: integration of

You can use power formula:
$\displaystyle \int \dfrac{(3 - x) \, dx}{(x^2 - 6x - 9)^{5/2}}$

      $= \displaystyle \int (x^2 - 6x - 9)^{-5/2} \, (3 - x) \, dx$

      $= \displaystyle -\dfrac{1}{2} \int (x^2 - 6x - 9)^{-5/2} \, [ \, -2(3 - x) \, ] \, dx$

      $= \displaystyle -\dfrac{1}{2} \int (x^2 - 6x - 9)^{-5/2} \, (2x - 6) \, dx$