Question

A+b=100,b+c=110,a+c=90
Aflati a b c

Answer 1

a+b=100 => a= 100-b 
b+c=110 => c=110-b
a+c=90 => a=90-c
egalam cele doua ecuatii ale lui a => 100-b=90-c => b-c = 100-90 => b-c = 10
si il inlocuim pe c => b-110+b=10 => 2b = 120 => b= 60 => c= 50 => a= 40