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7 elevi au sume de bani consecutive afla suma stiind ca ultimul dacă are cu 21 mai mult are de doa ori mai mult decât primul

Răspuns :

a=un segment
b=un segment+1 (a+1)
c=un segment+1+1(a+2)
d=un segment+1+1+1(a+3)
e=un segment+1+1+1+1(a+4)
f=un segment+1+1+1+1+1(a+5)
g=un segment+1+1+1+1+1+1(a+6)

a+6+21=ax2
a+27=ax2
2a=54
a=54:2
a=27
proba:
daca g+21=ax2
g=27+6+21=54
a=27x2=54


a=27
b=28
c=29
d=30
e=31
f=32
g=33

27+28+29+30+31+32+33=55+59+63+33=114+96=210

sper sa fie bine



A+b+c+D+e+f+g = 7elevi

B= a+1
C=a+2
D=a+3
E=a+4
F=a+5
G=a+6

2a= g+21
2a= a+6+21
2a= a+27
A= 27
B= 28
C=29
D=30
E= 31
F=32
G=33

Proba?
2a= g+21 ?
2x27= 33+21 ?
54= 54
Sper ca te-am ajutat !