Natali Belska
Гений
(67332)
1 месяц назад
[a - (a^2 + 2)/(a - 1)] * (1 - 2a + a^2)/(a + 2) =
= [a*(a - 1) - a^2 + 2]/(a - 1) * (1 - a)^2/(a + 2) =
= (a^2 - a - a^2 + 2)/(-1)(1 - a) * (1 - a)^2/(a + 2) =
= (a - 2)/(a - 1) * (a - 1)^2 /(a + 2) =
= (a - 2)/(a + 2) * (a - 1)^2 /(a - 1) =
= (a - 2)(a - 1) / (a + 2)