Question

daca 14 caciuli Si 10 fulare costa618 lei iar 7 caciuli si24 fulare costa 632 lei sa se afle cat costa 5 caciuli Si 5 fulare.

Answer 1

14 c.........10 f..........618 lei
7 c..........24 f...........632 lei |×2

14 c........48 f............1 264 lei
14 c..........10 f..............618 lei
______________________________ ( - )

38 f.............646 lei

un f = 646:38 = 17 lei
o c= [618-(10×17)]:14 =
       (618-170):14 =
        448:14 = 32 lei
o c=32 lei

5 c = 5×32 = 160 lei
5 f = 5×17 = 85 lei
f-fular  c-caciula

Answer 2

5c+5f=?
{14c+10f=618
{7c+24f=632 |×(-2)

{14c+10f=618
{-14c-48f=-1264

14c-14c+10f-48f=618-1264
0-38f=-646
-38f=-646 |:(-38)
f=17
14c+10f=618
14c+10×17=618
14c+170=618
14c=618-170
14c=448
c=448:14
c=32
5c+5f=5×32+5×17=5(32+17)=5×49=245