Răspuns :
1.2p - 20%·1.2p = 460.8
1.2p - 0.2·1.2p = 460.8
1.2p - 0.24p = 460.8
0.96p = 460.8
p = 480 lei (pretul initial)
p =pretul initial ;
p+px20/100 = p+p/5 = 6p/5 pretul dupa scumpire
6p/5-(6p/5)x20/100 = 6p/5 - (6p/5)x1/5 = 6p/5-6p/25 = 460,8 numitor comun 25
30p-6p = 11520 ; 24p = 11520 ; p = 11520/24 = 480 lei