Răspuns:
28-a>15=>a=28-15-1=13-1=12=>28-12>15
28-a>15=>a=28-15-2=13-2=11=>28-11>15
28-a>15=>a=28-15-3=13-3=10=>28-10>15
28-a>15=>a=28-15-4=13-4=9=>28-9>15
28-a>15=>a=28-15-5=13-5=8=>28-8>15
28-a>15=>a=28-15-6=13-6=7=>28-7>15
28-a>15=>a=28-15-7=13-7=6=>28-6>15
28-a>15=>a=28-15-8=13-8=5=>28-5>15
28-a>15=>a=28-15-9=13-9=4=>28-4>15
28-a>15=>a=28-15-10=13-10=3=>28-3>15
28-a>15=>a=28-15-11=13-11=2=>28-2>15
28-a>15=>a=28-15-12=13-12=1=>28-1>15
28-a>15=>a=28-15-13=13-13=0=>28-0>15
R:a={1,2,3,4,5,6,7,8,9,10,11,12,13}
#Împreunasuntembrainly
