Question

pt 4 acadele si 3 ciocolati, mama a platit 20 lei.In alta zia cumparat4 acadeles si 5 ciocalate si a platit 28 lei. cat costa o acadea? Dar o ciocolata

Answer 1

Notam acadelele cu a si ciocolata cu c
4a+3c=20
4a+5c=28=>a=(28-5c)/4
4(28-5c)/4+3c=20
28-5c+3c=20
8=2c
c=4
a=(28-20)/4
a=8/4
a=2