Question

calculati numerele naturale x stained ca 2(x+1)-1 este divizor al numarului 15

Answer 1

x=? daca 2(x+1)-1€D15
=>2(x+1)-1€{1,3,5,15}|+1
2x+2€{2,4,6,16}|-2
2x€{0,2,4,14}|:2
x€{1,2,7}