Explicație pas cu pas:
Prima oara lucram numaratorul
V(7+4V3)=V(4+4V3+3)=V(2+V3)²=|2+V3|=
2+V3
V(19-8V3)=V(16-8V3+3)=V(4-V3)²=|4-V3|=
4-V3
Deci la numarator avem 2+V3+4-V3=6
6/(x-3)€Z <=>x-3€D6 in Z =>
x-3€{-6,-3,-2,-1,1,2,3,6} =>
x€{-3,0,1,2,4,5,6,9}
x€N* => S={-3,1,2,4,5,6,9} => A={-3,1,2,4,5,6,9}