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)²/4с
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