Răspuns :
x-pretul initial
20% din x= 20/100* x= 1/5 * x= x/5 -scumpirea
x + x/5= (5x+x)/5 =6x/5 -noul pret
6x/5=480
x=5*480/6
x=5*80
x=400
20% din x= 20/100* x= 1/5 * x= x/5 -scumpirea
x + x/5= (5x+x)/5 =6x/5 -noul pret
6x/5=480
x=5*480/6
x=5*80
x=400
x-pretul initial
100/100ori x + 20/100 ori x=480,120/100 ori x=480, simplificam, 6/5x=480, x= 480ori5:6=400
100/100ori x + 20/100 ori x=480,120/100 ori x=480, simplificam, 6/5x=480, x= 480ori5:6=400