Question

Va rog frumos..... este urgent...

Mircea si Victoria au impreuna 77 kg, Victoria si Alina au impreuna 65 kg, iar Mircea si Alina au impreuna 74 kg. Cate kg cantareste fiecare copil?

Answer 1

a=Mircea
b=victoria
c=Alina
a+b=77   a=77-b
b+c=65  c=65-b
a+c=74  77-b+c=74, 77-b+65-b=74 142-2b=74; 142-74=2b
68=2b
b=68:2=34
a= 77-34=43
c=65-34=31

Answer 2

M + V = 77
V + A = 65
M + A = 74
le adunam
2(M + V + A) = 216    | : 2
M + V + A = 108
77 + A = 108
A = 108 - 77
A = 31 KG
V = 65 - 31
V = 34 KG
M = 74 - 31
M = 43 KG