Question

Doru are hamsteri si papagali,în total 7 capete si 22 de picioare.Câti hamsteri şi papagali are Doru?

Answer 1

h+p=7
2h+4p=22
2*h+2*p=22
2*(h+2p)=22
h+2p=22:2
h+2p=11
h+p=7
scadem
h-h=0
2p-p=p
11-7=4
p=4
h+4=7
h=7-4
h=3