Răspunsuri

2014-11-16T16:23:53+02:00
D20={1,2,4,5,10,20}
20 :(x+3)
x+3=1=> x=-2
x+3=2=> x=-1
x+3=4=> x=1
x+3=5=> x=2
x+3=10=> x=7
x+3=20=> x=17
x={1,2,7,17}