Question

Raluca ,si Maria si Petru au cheltuit inpreuna 1000 de lei Raluca si Maria au cheltuit 640 de lei ,iar Maria si Petru au cheltuit 750 de lei .Cati lei a cheltuit fiecare copil?

Answer 1

r+m+p=1000
r+m=640
m+p=750

1000-640=360 p
750-360=390 m
640-390=250 r

Answer 2

R+m+p=1000 R+m=640 M+p=750 Inlocuim in prima si vine r+750=1000 R=250 M=640-250=390 Acum scoatem p 390+p=750 P=360 Verif 360+390+250=1000