Question 42080
You work this one like anyother fraction you must first find the LCD but to do this you need to factor the denominator

{{{(3/(x^2+4x+3))-(1/(x^2-9))}}}
{{{(3/(x+3)(x+1))-(1/(x-3)(x+3))}}}  now you can see that the LCD is (x+3)(x+1)(x-3)
{{{((3x-9)/(x+3)(x+1)(x-3))-((x+1)/(x+3)(x+1)(x-3))}}}  Now you can subtract fractions.
{{{((3x-9)-(x+1))/((x+3)(x+1)(x-3))}}}
{{{(3x-9-x-1)/((x+3)(x+1)(x-3))}}}
{{{(2x-10)/((x+3)(x+1)(x-3))}}}  That is the answer since you can not get it any simpler.