Сократите дроби: 1.m-n/(n-m)^2 2.х^2-2х+1/х^2-1 3.5m+10mn+5n^2/15m^2-15n^2 4.a^2+aв+в^2/а^3-в^3

(m-n)/(n-m)²=-(n-m)/(n-m)³=-1/n-m=1/m-n
x²-2x+1/x²-1=(x-1)²/(x-1)(x+1)=x-1/x+1
5m²+10mn+5n²/15m²-15n²=5(m²+2mn+n²)/15(m²-n²)=5(m+n)²/15(m-n)(m+n)=m+n/3(m-n)
a²+ab+b²/a³-b³=a²+ab+b²/(a-b)(a²+ab+b²)=1/a-b