Question

Afla c+ b + a , daca : 
a + b = 236
b + c = 632 
a + c = 708

Answer 1

a+b=236
b+c=632
a+c=708
adunam toate relatile si ne da:
2a+2b+2c=1576 impartim prin 2
a+b+c=788
c+b+a=788

Answer 2

m = 236, n =  632 si p =  708

a + b = m
b + c = n
a + c = p

a + b + c = ?
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a + b + 2c = n+ p => m + 2c = n + p => c = (n + p - m) / 2
(n + p - m) / 2 = c
(p + m - n) / 2 = a
(m + n - p)  / 2 = b
(n + p - m + p + m - n + m + n - p) / 2 = c + a + b
 (n + p + m) / 2 = c + a + b
(236 + 632 + 708) / 2 = 788 = c + a + b

a + b + c = 788