Răspuns :
a+b=35
a+5b=115 ⇒a=115-5b
115-5b+b=35 ⇒115-4b=35
4b= 115-35=80
b=80:4=20
a=35-b=35-20=15
a=15
b=20
a+b=35 rezultă a=35-b
a+5b=115
35-b+5b=115
4b=115-35
b=80:4
b=20
a=35-20=15
a+5b=115
35-b+5b=115
4b=115-35
b=80:4
b=20
a=35-20=15