3 mingi.........7 masinute.......224 lei
3 mingi..........4 masinute..... .146 lei
___________________________ ( - )
//....... 3 masinute........78 lei
Aflam cat costa o masinuta
78:3 = 26 lei
Aflam cat costa 7 masinute
26×7 = 182 lei
Aflam cat costa o minge
( 224-182) : 3 = 42 : 3 = 14 lei
Verificare:
3×14 + 7×26 = 42+182 = 224
3×14 + 4×26 = 42 + 104 = 146