Answer
(x-y)(x+2y)
Work Step by Step
$x^{2}$ +xy-2$y^{2}$=$x^{2}$ +2xy-xy -2$y^{2}$ becouse xy=2xy-xy
($x^{2}$ +2xy)+(-xy -2$y^{2}$ )=
x(x+2y)-y(x+2y)=(x-y)(x+2y)
You can help us out by revising, improving and updating this answer.
Update this answerAfter you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.