Question

Найдите значение выражения: a^2+b^2-ab/x^2-y^2 : a^3+b^3/x^2+y^2-2xy

Answer 1

(a^2 - ab + b^2)/( x - y)(x + y) * (x- y)(x - y) / ( a + b)(a^2 - ab + b^2) = 
= 1/( x + y) * (x- y)/ ( a + b) = ( x - y) / ( x +y)(a + b)

Answer 2

(a²+b²-ab)/(x²-y²) : (a³+b³)/(x²+y²-2xy)=
=(a²+b²-ab)/(x+y)(x-y) . (x-y)²/(a+b)(a²-ab+b²)=
=(a²-ab+b²)(x-y)(x-y)/(x+y)(x-y)(a+b)(a²-ab+b²)=
=(x-y)/(x+y)(a+b)