Question

Rezolvati ex repede e urgent dau 20 puncte

Answer 1

2x-1⊂{1;2;3;6;9;18}
2x-1=1...2x=2...x=1∈N
2x-1=2 2x=3....x∉N
2x-1=3...x=2∈N
2x-1=6...x∉N
2x-1=9...x=5∈N
2x-1=18...x∉N
deci x∈{1;2;5}