Răspuns :
a+b=7,21
a-b=2,15
a=2,15+b
2,15+b+b=7,21
2b=7,21-2,15
2b=5,06
b=2,53
a=2,15+2,53=4,68
a-b=2,15
a=2,15+b
2,15+b+b=7,21
2b=7,21-2,15
2b=5,06
b=2,53
a=2,15+2,53=4,68
a+b=7,21
a-b=2,15
a=2,15+b
2,15+b+b=7,21
2,15+2b=7,21
2b=7,21-2,15
2b=5,06
b=5,06:2
b=2,53
a=7,21-2,53
a=4.68
a-b=2,15
a=2,15+b
2,15+b+b=7,21
2,15+2b=7,21
2b=7,21-2,15
2b=5,06
b=5,06:2
b=2,53
a=7,21-2,53
a=4.68