Răspuns:
Metoda comparatiei adaptata:
1kg tort----------------=--------------3kg fursecuri / inmultim cu 2
2kg tort----------------+-----4kg fursecuri-----=70 lei
Obtinem:
2kg tort----------------=--------------6kg fursecuri
2kg tort----------------+-----4kg fursecuri-----=70 lei
Punem in loc de 2kg de tort 6kg de fursecuri (inlocuim). Obtinem:
6kg fursecuri----------------+-----4kg fursecuri-----=70 lei
Atunci:
10kg fursecuri=70 de lei
Atunci:
1kg fursecuri=70lei:10
1kg fursecuri=7lei
Dar am vazut ca
1kg tort----------------=--------------3kg fursecuri
3kg fursecuri=3×7 lei
3kg fursecuri=21 lei
Deci 1kg tort=21 de lei.
Facem proba:
2kg tort----------------+-----4kg fursecuri-----=70 lei
2×21+4×7=42+28=70
