Răspuns :
(a+b)/2=3.09
a+b=6.18
a=2b
2b+b=6.18
3b=6.18
b=6.18:3
b=2.06
a=2.06*2
a=4.12
a+b=6.18
a=2b
2b+b=6.18
3b=6.18
b=6.18:3
b=2.06
a=2.06*2
a=4.12
3.09*2=6.18
6.18:3=2.06
2.06*2=4.12
verificare:(4.12+2.06):2=3.09
6.18:3=2.06
2.06*2=4.12
verificare:(4.12+2.06):2=3.09