Question

va rog am nevoie irgent de rezolvare

Answer 1

notam cu C=pret carte si cu c=pret caiet
C+c=60lei
dupa o saptamana cartea costa C-10%C=90%C=9/10*C
dupa o saptamana caietul costa c+10%C=110%c=11/10*c
dupa o saptamana cele 2 costa
56=9/10*C+11/10*c
       9C+11c=560lei
dar C+c=60lei  c=60-C
inlocuim a doua ecuatie in prima
9C+11(60-C)=560
9C+660-11C=560
2*C=100
C=50lei
si c=60-50=10lei
b)
dupa o saptamana cartea costa C-10%C=90%C=9/10*C=9/10*50=45 lei
dupa o saptamana caietul costa c+10%C=110%c=11/10*c=11/10*10=11lei