Răspuns :
a:6=c₁r3=>a=6c₁+3
a:15=c₂r3=>a=15c₂+3
a=[6,15]+3
6=2x3
15=3x5
a=2x3x5+3
a=33
verificare:33:6=5r3 ; 33:15=2r3
a:15=c₂r3=>a=15c₂+3
a=[6,15]+3
6=2x3
15=3x5
a=2x3x5+3
a=33
verificare:33:6=5r3 ; 33:15=2r3