Răspuns :
3p+5s=235lei
6p+15s=690lei
3(2p+5s)=690lei / :3 => 2p+5s=230 lei
3p+5s=235lei => p = 235-230 = 5lei
3*5+5s=235lei
15+5s=235lei
5s=235-15=220lei
s=220:5=44lei
(s=pretul unui stilou, p=pretul unui pix)
6p+15s=690lei
3(2p+5s)=690lei / :3 => 2p+5s=230 lei
3p+5s=235lei => p = 235-230 = 5lei
3*5+5s=235lei
15+5s=235lei
5s=235-15=220lei
s=220:5=44lei
(s=pretul unui stilou, p=pretul unui pix)
2pixuri+10stilouri=690-235
=455 lei
1 pix+5 stilouri=455-235=220lei
2 pix +0 stilouri=235-220=15lei(2stilouri=15lei
=455 lei
1 pix+5 stilouri=455-235=220lei
2 pix +0 stilouri=235-220=15lei(2stilouri=15lei