2. ответ: -4/(m²-4),
1) (m+1)/(2m-2) - 1/(m-1) = (m+1)/(2m-2) - 2/(2m-2) = (m+1-2)/(2m-2) =
= (m-1)/(m-1)*2 = 1/2,
2) 1/(m-2) : 1/2 = 1/(m-2) * 2 = 2/(m-2),
3) 2m/(m²-4) - 2/(m-2) = 2m/(m-2)(m+2) - 2/(m-2) =
= 2m/(m-2)(m+2) - 2(m+2)/(m-2)(m+2) = (2m-2m-4)/(m-2)(m+2) = -4/(m²-4),