Răspuns:
notam cu:
c-ciocolata,
p- prajituri
6c + 13pi = 5100g
5c + 9p = 3700g
---------------------------
1c + 4p= 1400g
1c=1400-4p
6x (1400-4p)+13p=5100
8400-24p+13p=5100
8400-5100= 24p-13p
11p =3300 g
p=3300/11
p=300g 6c+13x300=5100
6c=5100-3900
6 c =1200
c=1200/6
c=200g
5 ciocolate si trei prajituri cantaresc:
5x200+3x300=1900g
Explicație pas cu pas: