Question

trei stilouri si 4 penare costa 440leiiar 5 stilouri si 2 penare costa 500 lei. Cat costa un penar si doua stilouri?

Answer 1

3 stilouri +4 penare = 440 lei
5 stilouri + 2 penare = 500 lei  ( il amplificam cu 2 ) ⇒10s + 4p = 1000 lei
10s - 3s + 4p - 4p =1000-440
7s + 0 =560 lei
stilou=80 lei
3x80+4p=440
240+4p=440
4p=200
penar=50 lei
2 stilouri = 80+80 =160 lei

Answer 2

 3s + 4p =440lei
 5s + 2p = 500lei (dublam suma)
10s + 4p = 1000lei
1000lei- 440lei= 560lei
 7s=560lei
 560lei:7=80lei (1s)
 80lei x 2=160lei (2s)
 160lei+80lei=240lei(3s)
 440lei-240lei=200lei(4p)
 200lei:4=50lei (1p)
  Raspuns:1p=50lei
                 2s=160lei