Te ajut eu.
a.
4x<12=>x<12:4=>x<3=>x e (apartine) {0,1,2}
b.
2x<8=>x<8:2=>x<4=>x e {0,1,2,3}
c.
5x<10=>x<10:5=>x<2=>x e {0,1}
d.
122x<122=>x<122:122=>x<1=>x e {0}
e.
24x<120=>x<120:24=>x<5=>x e {0,1,2,3,4}
f.
18x<126=>x<126:18=>x<7=>x e {0,1,2,3,4,5,6}
g.
326x<1304=>x<1304:326=>x<4=>x e {0,1,2,3}
