ex 4 am nevoie va rog rapid de rezolvare dau coroană

A={5,11,21/3}
B={-8,5,-4,11,-1,21/3,-21/3}
C={5,11,21/3}
D={-8,-4,-21/3}
E={-8,-4,-3/4,-4/11,-21/3}
F={3\4,5,9/2,10/3,8/3,4/11,21/3}
Sper ca te.am ajutat!