Răspuns :
2a.......7e=40-
2a.......3e=24
------------------------
/...........4e=16=>e=16:4=>e=4 lei costa un ecler
2a+7·4=40=>2a=40-28=>a=12:2=>a=6 lei costa o amandina
2a.......3e=24
------------------------
/...........4e=16=>e=16:4=>e=4 lei costa un ecler
2a+7·4=40=>2a=40-28=>a=12:2=>a=6 lei costa o amandina