Question

daca a+b=36 b+c=57 a+c=51 calculati c-a-b

Answer 1

a+b=36 ; b+c=57 ; a+c=51
b=(b+c)-(a+b)
b=57-36
b=21
a+b=36
a+21=36
a=36-21
a=15
a+c=51
15+c=51
c=51-15
c=36
c-a-b=36-15-21=21-21=0

Answer 2

Din fiecare ecuatie scoatem a,b,c
a+b=36=>b=36-a
b+c=57=>c=57-b
a+c=51=>a=51-c
 Si acum inlocuiesti in c-a-b
57-b-51+c-36-a=0
-b+c-a=36+51-57
Si acum le punem in ordine -b+c-a este echivalent cu c-a-b
deci c-a-b=87-57
c-a-b=30