Question 222637
{{{(3x)/(x^2-4)}}} + {{{(3+x)/(x+2)}}}
The first denominator is "difference of squares" factor it 
{{{(3x)/((x-2)(x+2))}}} + {{{(3+x)/(x+2)}}}
We can see the common denominator is: (x-2)(x+2) so we have
{{{((3x) + (x-2)(3+x))/((x-2)(x+2))}}}
FOIL
{{{((3x) + (3x + x^2 - 6 -2x))/((x-2)(x+2))}}}
group like terms and combine
{{{((x^2 + 3x + 3x - 2x - 6))/((x-2)(x+2))}}} = {{{((x^2 + 4x - 6))/((x-2)(x+2))}}}
Foil the denominator to get the original denominator
{{{((x^2 + 4x - 6))/(x^2-4)}}}