Răspuns :
7/(2x+1) apartine lui N*
=> 2x+1 ={1,7}
2x+1=1 <=> 2x=0, deci x=0
2x+1=7<=> 2x=6, deci x=3
A={0,3}
=> 2x+1 ={1,7}
2x+1=1 <=> 2x=0, deci x=0
2x+1=7<=> 2x=6, deci x=3
A={0,3}