2x^2−5xy+y^2 - (x^2+4xy −3y^2)
= 2x^2−5xy + y^2 - x^2 - 4xy + 3y^2
= x^2 - 9xy + 4y^2
answer
x^2 - 9xy + 4y^2
if you combine your like terms you would get -xy-x^2-2y^2. hope that helps!
