Question

Determina nr a, b, c stiind ca a+b=700, b+c=500, a+c=800

Answer 1

Pai aduni toate relatiile =>
a+b+b+c+a+c=700+500+800 => 2*a+2*b+2*c=2000
Imparti totul la 2 => a+b+c=1000.
Din a+b+c=1000 si a+b=700 => c=1000-700=300.
b+c=500 => b+300=500 => b=200. 
a+c=800 => a+300=800 => a=500.