Ответ:
Объяснение:
1. a) (5ab)/(15b)=a/3; б) (6m(2-n))/(3m²(n-2))=(-2(n-2))/(m(n-2))=-2/m
2. a) (12x-3)/(24x²-6x)=(3(4x-1))/(6x(4x-1))=1/(2x)
б) (y+5)/(y²+10y+25)=(y+5)/(y+5)²=1/(y+5)
в) (a²-4a+4)/(a²-4)=(a-2)²/((a-2)(a+2))=(a-2)/(a+2)
г) (n²-n+1)/(n³-n²+n)=(n²-n+1)/(n(n²-n+1))=1/n
3. При x=5/6:
(9x²-1)/(1+6x+9x²)=((3x-1)(3x+1))/(3x+1)²=(3x-1)/(3x+1)=(3·5/6 -1)/(3·5/6 +1)=(2,5-1)/(2,5+1)=15/35=3/7