If f(x)=6/x and g(x)= 3/(x+13), find (fg)(x).

9/(2x+13)

9/(x^{2}+13)

18/(x^{2}+13x)

18/(2x+13)

Multiply the two functions as you would two numbers:

(fg)(x)=f(x)g(x)=(6/x) ×(3/(x+13)=18/(x*(x+13))=18/(x^{2}+13x)