Question

Afla c+b+a dacă
a+b=236
b+c=632
a+c=708

Answer 1

$\rm a+b=236 \\b+c=632 \\a+c=708 \\ ------(+) \\ 2a+2b+2c=236+632+708 \\ 2a+2b+2c=1576|:2 \\ \bold{a+b+c=788}$

Answer 2

a+b=236
b+c=632
a+c=708
_________      observam ca avem
2a + 2b + 2c =236+632+708=1576
a+b+c = 1576/2=788 - suma celor trei nr sau c+a +b