Answer:
[tex]-(x-y)^2[/tex]
Step-by-step explanation:
Original expression:
[tex]-x^2+2xy-y^2[/tex]
Factor out -1:
[tex]\implies -(x^2-2xy+y^2)[/tex]
Factor [tex]x^2-2xy+y^2[/tex]:
[tex]\implies -(x-y)(x-y)[/tex]
Apply exponent rule [tex]aa=a^2[/tex]:
[tex]\implies -(x-y)^2[/tex]
