Ответ:
Объяснение:
а) (x-25)/(5x-25) +(3x+5)/(x²-5x)=(x-25)/(5(x-5)) +(3x+5)/(x(x-5))=(x²-25x+15x+25)/(5x(x-5))=(x²-10x+25)/(5x(x-5))=(x-5)²/(5x(x-5))=(x-5)/(5x)
б) (12-y)/(6y-36) -6/(y²-6y)=(12-y)/(6(y-6)) -6/(y(y-6))=(12y-y²-36)/(6y(y-6))=-(y-6)²/(6y(y-6))=-(y-6)/(6y)
в) 1/(a²+ab) +1/(ab+b²)=1/(a(a+b)) +1(b(a+b))=(b+a)/(ab(a+b))=1/(ab)
г) 1/(b²-ab) -1/(ab-a²)=1/(b(b-a)) -1/(a(b-a))=(a-b)/(ab(b-a))=-1/(ab)