x/5 - mere
x-x/5=4x/5 - rest
4x/5·1/2=2x/5 - piersici
x-x/5-2x/5=2x/5 - rest
2x/5·1/4=x/10- prune
x/5+2x/5+x/10+2·15=x
2x+4x+x+300=10x
300=10x-7x
x=300:3
x=100 lei a avut Roxana
100:5=20 lei au costat merele
100-20=80 lei rest
80:2=40 lei au costat piersicile
100-(20+40)=40 rest
40:4=10 lei au costat prunele
2·15=30 lei au costat caisele
proba:20+40+10+30=100 lei suma initiala
