Va rog urgent multumesc anticipat va roggg

Explicație pas cu pas:
a) 1230,1233,1236,1239
b) 2502,2511,2520,2529,2538,2547,2556,2565,2574,2583,2592
c) cu 10=6300,6310,6320,6330,6340,6350,6360,6370,6380,6390;
Cu 9=6300,6309,6318,6327,6336, 6345,6354,6363,6372,6381,6390,6399