Ответы

15
1)1/x²-1/y²=(y²-x²)/9x²y²)
2)(y²-x²)²/(x+y)²*x²y²/(y²-x²)=(y²-x²)/(x+y)²*x²y²=(y-x)9y+x)/(x+y)²*x²y²=
=x²y²(y-x)/(x+y)
16
1)1/a+1/b=(b+a)/ab
2)(a+b)²-(a-b)(a²+ab+b²)/(a-b)=(a+b)²-(a²+ab+b²)=a²+2ab+b²-a²-ab-b²=ab
3)(a+b)/ab*ab=a+b
Нет комментариев