Answer:
5x-12 / (x+3)(x-3)
Explanation:
Given expression:\frac{3}{x^2-9}+\frac{5}{x+3}
Using identity a^2-b^2=(a+b)(a-b), we get
=\frac{3}{(x+3)(x-3)}+\frac{5}{x+3}
Taking L.C.M. of the denominator, we get
\frac{3+5(x-3)}{(x+3)(x-3)}=\frac{3+5x-15}{(x+3)(x-3)}
=\frac{5x-12}{(x+3)(x-3)}
\Rightarrow\frac{3}{x^2-9}+\frac{5}{x+3}=\frac{5x-12}{(x+3)(x-3)}