a+(a+2)+(a+4)+(a+6)+ (a+8)=55
a+a+2+a+4+a+6+a+8=55
5a+20=55
5a=55-20
5a=35
a=35:5
a=7 Numerele sunt: 7; 9; 11; 13; 15.
Sau folosind segmentele:
1. l_____l
2. l_____l+2
3. l_____l+4
4. l_____l+6
5. l_____l+8 Egalam numerele: 55-(2+4+6+8)=55-20=35
Primul numar: 35:5=7
Al doilea numar: 7+2=9 ........