Question

3 banane si 5 mineole cantaresc impreuna 810 g.Cat cantareste fiecare,daca o banana si o mineola cantaresc (impreuna) 220 g?

Answer 1

Metoda comparatiei

3 banane .................5 mineole ..............810 g

o banana .................o mineola ..............220 g l x 3

_________________________________________

3 banane ................ 5 mineole .............810 g

3 banane ................ 3 mineole ............660 g

___________________________________ → le scad

/ 2 mineole .....................150 g

150 g : 2 = 75 g → cantareste o mineola

220 g - 75 g = 145 g → cantareste o banana

sau

b + m = 220 g ⇒ b = 220 - m

3 b + 5 m = 810 g

3 ( 220 - m ) + 5 m = 810

660 - 3 m + 5 m = 810

2 m = 810 - 660

m = 150 : 2 = 75 g → cantareste o mineola

220 g - 75 g = 145 g → cantareste o banana