221х²-60х+4=0
D=3600-16*221=64
х1=(60+8)/442=34/221 х2=52/442=26/221
((1+√3)²-3-(1-√3)²+3)/((1-√3)²-3-(1+√3)²+3)=
=(1+2√3+3-3-1+2√3-3+3)/(1-2√3+3-3-1-2√3-3+3)=4√3/-4√3=-1
|a-c| - |a+c| - |c-a| + |-c-a| = (|a-c| - |a-c|) + (|a+c| + |c+a|) = 2|a+c|
|a-b| - |b-a| = |a-b| - |a-b| = 0
Х4-19х2+48=0
х2=t
t2-19t+48=0