Suma a 7 numere naturale impare consecutive este 119.Aflati numerele.
Va rog frumos sa ma ajutati.


Răspuns :

Faci cu segmente.
7a=119-42
7a=77
a=11
b=13
c=15
d=17
e=19
f=21
g=23

2k+1+2k+3+2k+5+2k+7+2k+9+2k+11+2k+13=119

14k+49=119

14k=119-49

14k=70

k=5

2k+1=2*5+1=10+1=11

2k+3=2*5+3=10+3=13

2k+5=2*5+5=10+5=15

2k+7=2*5+7=10+7=17

2k+9=2*5+9=10+9=19

2k+11=2*5+11=10+11=21

2k+13=2*5+13=10+13=23