Question

a+b+c=840 a+b=642 b+c=553 a+b+c?

Answer 1

Daca a+b+c=840; a+b=642; b+c=553;
Atunci ar fii doua posibilitati:
1) 642+c=840
c=840-642
c=198

2) a+553=840
a=840-553
a=287
PROBA:
1) 642+198=840
2) 287+553=480
Sau:
a+b+c =840 
a+b=642 
b+c=553
a= 840-553
a= 287
b=642-287
b= 355
c=840-642
c=198
Probă : 287+355+198=840
a=287
b=355
c=198

Answer 2

a+b+c =840
a+b=642
b+c=553
a= 840-553
a= 287
b=642-287
b= 355
c=840-642
c=198
Probă : 287+355+198=840
a=287
b=355
c=198