Question

trei cuburi si 8 bile cantaresc 150 g. ,iar 3 cuburi si 4 bile cantaresc 90 g.Cat cantareste fiecare? prin metoda comparatiei. va rog frumos!!!!!

Answer 1

3c + 8b = 150
3c + 4b = 90
le scadem
  /    4b = 60
b = 60 : 4
b = 15 g bila
3c + 4 * 15 = 90
3c = 90 - 60
c = 30 : 3
c = 10 g un cub

Answer 2

3 cuburi+8 bile=150 grame
3 cuburi+4 bile=90 grame
------------------------
8 bile-4 bile=150-90 grame
4 bile=60 grame
1 bila=60:4=15 grame

8 bile=15•8=120 grame
3 cuburi=150-120=30 grame
1 cub=30:3=10 grame