Răspuns :
a+42+a+35+a+28+a+21+a+14+a+7=171
6a+147=171
6a=171-147
a=24:6
a=4
4+7=11
11+7=18
18+7=25
25+7=32
32+7=39
39+7=46
nr sunt 11,18,25,32,39,46
6a+147=171
6a=171-147
a=24:6
a=4
4+7=11
11+7=18
18+7=25
25+7=32
32+7=39
39+7=46
nr sunt 11,18,25,32,39,46