Упростите выражение: (√с/2-1/2√с) ^2 (√c-1/√c+1-√c+1/√c-1)

1) √с/2-1/2√с = (с-1) / 2√с

2) [ (с-1) / 2√с]² = (с-1) ²/4 с

3) (√c-1) / (√c+1) - (√c+1) / (√c-1) = (c-2√c+1-c-2√c-1) / (c-1) = - 4√c / (c-1)

3) (c-1) ²/4c * (-4√c) / (c-1) = - (c-1) / √c = (1-c) / √c