Answer
$\frac{(x+3y)}{(2x+y)}$
Work Step by Step
Since the numerator and the denominator both consist of a trinomial, we use the rules of factoring trinomials in order to factor them. Then, we cancel out the resultant common factors in the numerator and the denominator:
$\frac{x^{2}+2xy-3y^{2}}{2x^{2}-xy-y^{2}}$
=$\frac{x^{2}-1xy+3xy-3y^{2}}{2x^{2}+1xy-2xy-y^{2}}$
=$\frac{x(x-y)+3y(x-y)}{x(2x+y)-y(2x+y)}$
=$\frac{(x-y)(x+3y)}{(2x+y)(x-y)}$
=$\frac{(x+3y)}{(2x+y)}$
