The least common denominator (LCD) for the expression
is (x+1)(x-2). Multiply both terms by this LCD, get...
[(3(x+1)(x-2))/(x+1)] + [(5(x+1)(x-2))/(x-2)]
3(x-2)+5(x+1).........first term (x+1)/(x+1) cancels, second
term (x-2)/(x-2) cancels, both are 1
3x-6+5x+5..............distribute
8x-1........................combine like terms
So the simplified expression for 3/(x+1) + 5/(x-2) is 8x-1.
