Răspuns:
a) a+b=100
b+c=110
a+c= 90
2×(a+b+c)=300
a+b+c= 150
100+c =150
c=50 (100-50)
b+50 =110
b= 60 (110-50)
a+60=100
a=40 (100-60)
Răspuns: a=40
b=60
c=50
Verificare: 40+60=100
60+50=110
40+50=90
b) a+b=84
b+c=64
a+c=34
2×(a+b+c)= 182
a+b+c=182:2
a+b+c=91
84+c=91
c=7 (91-84)
b+7=64
b= 57 (64-7)
a+b=84
a=27 (84-57)
Raspuns : a=27
b=57
c= 7
Verificare : 27+57= 84
57+7=64
27+7= 34