we have that
(4/(x²-9))+(7/(x+3))
(x²-9)-------------> (x+3)*(x-3)
then
4/[(x+3)*(x-3)]+7/[x+3]
step 1
find the LCD first and then combine
[4+7*(x-3)]/[(x+3)*(x-3)]-------> [4+7x-21]/[(x+3)*(x-3)]
=[7x-17]/[(x+3)*(x-3)]
the answer is
[7x-17]/[(x+3)*(x-3)]
