Question 135286
{{{(2)/(x+3)+(5)/(3-x)-(6)/(x^2-9)}}}


First note that {{{3-x=-x+3=-(x-3)}}}, so you can re-write the entire expression as:


{{{(2)/(x+3)-(5)/(x-3)-(6)/(x^2-9)}}}


Second note that {{{x^2-9}}} is the difference of two squares and factors to {{{(x+3)(x-3)}}}.  Since this is just the product of the other two denominators, {{{x^2-9}}} is the lowest common denominator.


Now you can write:
{{{(2(x-3)-5(x+3)-6)/(x^2-9)}}}


Now all you need to do is clear the parentheses in the numerator and collect like terms.