Ответ:
11
Объяснение:
2x^2+7xy-9y^2/x^2-y^2 + 9x^2-7xy-2y^2/x^2-y^2=
x*(2x+9y)-y*(2x+9y)/(x-y)*(x+y) + x*(9x+2y)-y*(9x+2y)/(x-y)*(x+y)=
(2x+9y)*(x-y)/(x-y)*(x+y) +(9x+2y)*(x-y)/(x-y)*(x+y)=
2x+9y/x+y + 9x+2y/x+y= 2x+9y+9x+2y/x+y= 11x+11y/x+y= 11(x+y)/x+y=
11.