Question

22 de carti a cate 50 si 90 de pagini au impreuna 1340 de pagini . Cate carti sunt de fiecare fel?

Answer 1

    
[tex]Notatii: \\ x = numarul~de~carti~cu~50~pagini \\ y = numarul~de~carti~cu~90~pagini \\ x+y=22 ~~~~~~~=\ \textgreater \ ~~x=22-y\\ 50x+90y=1340 \\ --------- \\ 50(22-y)+90y = 1340 \\ 1100-50y+90y = 1340 \\ 40y=1340-1100 \\ 40y = 240 ~~~~~~~=\ \textgreater \ ~~~y=240:40= \boxed{6~carti~cu~90~de~pagini} \\ x=22-y = 22-6 = \boxed{16~carti~cu~50~de~pagini}[/tex]