Răspuns :
a+a+2+a+4+a+6+a+8=397-327
5a+20=70
5a=70-20
5a=50
a=50:5
a=10
nr sunt 10,12,14,16,18
verificare 10+12+14+16+18=22+14+16+18=36+16+18=52+18=70
5a+20=70
5a=70-20
5a=50
a=50:5
a=10
nr sunt 10,12,14,16,18
verificare 10+12+14+16+18=22+14+16+18=36+16+18=52+18=70
I: -------------------
II: ------------------- +2
III: ------------------- +2 + 2
IV: ------------------- +2 + 2 + 2
V: ------------------- +2 + 2 + 2 +2
Suma lor este: 397 - 327 = 70
70 - ( 2 x 10) = 70 - 20 = 50
50 : 5 = 10
I: 10
II: 10 + 2 = 12
III: 10 + 4 = 14
IV: 10 + 6 =16
V: 10 + 8 = 18
II: ------------------- +2
III: ------------------- +2 + 2
IV: ------------------- +2 + 2 + 2
V: ------------------- +2 + 2 + 2 +2
Suma lor este: 397 - 327 = 70
70 - ( 2 x 10) = 70 - 20 = 50
50 : 5 = 10
I: 10
II: 10 + 2 = 12
III: 10 + 4 = 14
IV: 10 + 6 =16
V: 10 + 8 = 18