rmember (a/b)/(c/d)=(a/b)(d/c)=(ad)/(bc)this is just alot of busy work
find f+g first then find f-g
f+g=(x-4)/(x+9)+(x-9)/(x+4) make denomenator the same multiply left one by (x+4)/(x+4) and right one by (x+9)/(x+9) [(x-4)(x+4)]/[(x+9)(x+4)]+[(x-9)(x+9)]/[(x+9)(x+4)] [x²-16]/[(x+9)(x+4)]+[x²-81]/[(x+9)(x+4)] [x²+x²-16-81]/[(x+9)(x+4)] [2x²-97]/[(x+9)(x+4)]
now f-g [x²-16]/[(x+9)(x+4)]-[x²-81]/[(x+9)(x+4)] [x²-x²-16+81]/[(x+9)(x+4)] [65]/[(x+9)(x+4)]
now we got [tex] \frac{ \frac{2x^2-97}{(x+9)(x+4)} }{ \frac{65}{(x+9)(x+4)} } [/tex] invert and multiply [tex](\frac{2x^2-97}{(x+9)(x+4)})(\frac{(x+9)(x+4)}{65})[/tex] [tex] \frac{2x^2-97}{65} [/tex]
