Question

Упростите
И выберите правильный вариант ответа

Answer 1

1)(x+y)(x²-xy+y²)/(x+y)*1/(x²-y²)=(x²-xy+y²)/(x²-y²)
2)(x²-xy+y²)/(x-y)(x+y)+2y(x+y)-xy/(x-y)(x+y)=
=(x²-xy+y²+2xy-2y²-xy)/(x²-y²)=(x²-y²)/(x²-y²)=1