Question

bunica a cumparat pentru nepoteie sai 3 carti,3 penare si 3 stilouri, platind in total 1239.Aflati cat a costat fiecare obiect ,stiind ca un penar era mai ieftin decat o carte cu 175 lei,iar 2 carti au costat cat 5 stilouri

Answer 1

3 *(p+s+c)=1239
p+c+s=1239:3=413
2c=5s
p=c-175
5p+5c+5s=413×5=2065
5p+5c+2c=2065
5p+10s+1c+2c=2065
5p+10s+3c=2065
5p=5c-5×175
5p=5c-875
5c-875+5c+2c=2065
5c+5c+2c-875=2065
12c-875=2065
12c=2065+875
12c=2940
1c=2940:12
1c=245
1p=245-175
1p=70
5s=2c
2c=5s
2×245=5s
5s=490
s=490:5
s=98