Question 735159
Least common denominator is 3(x+2)

To get that in {{{(-2x)/(x+2)}}} multiply numerator and denominator by 3/3 to get 
{{{3(-2x)/(3(x+2))=(-6x)/(3(x+2))}}}

For {{{x/3}}} multiply by {{{(x+2)/(x+2)}}} and get {{{(x(x+2))/(3(x+2))}}}

For {{{4/(x+2)}}} multiply by 3/3 to get {{{12/(3(x+2))}}}

So we are adding numerators {{{(-6x) + x(x+2) + 12 = -6x +x^2+ 2x + 12 = x^2-4x+12 }}}
Factor that to get {{{(x-6)(x+2)}}}

So we have {{{((x-6)(x+2))/(3(x+2))}}} which we can reduce by canceling the common factor of (x+2) in the numerator and denominator to get 

{{{(x-6)/3}}}