Răspuns :
a+b/2 =42 ; a+b =2*42 ; a+b =84
a =2b/5
2b/5 +b =84 numitor 5
2b +5b =420
7b =420
b =60
a =2b/5
a =2*60/5 =120/5 =24
verif ; 24+60 =84
a =2b/5
2b/5 +b =84 numitor 5
2b +5b =420
7b =420
b =60
a =2b/5
a =2*60/5 =120/5 =24
verif ; 24+60 =84