Răspuns :
x pret
x + 20% · x = x · ( 1 + 20 /100 ) = x · ( 1 + 1 / 5 ) = 6x / 5
6x / 5 - 20% · 6x / 5 = ( 1 - 20 /100 ) · 6x / 5 = ( 1 - 1 / 5 ) · 6x / 5
= 4 · 6x / 5 · 5 = 24x / 25
24x / 25 = 1248 lei
x = 25 · 1248 / 24 = 25 · 52 lei = 1300 lei
x + 20% · x = x · ( 1 + 20 /100 ) = x · ( 1 + 1 / 5 ) = 6x / 5
6x / 5 - 20% · 6x / 5 = ( 1 - 20 /100 ) · 6x / 5 = ( 1 - 1 / 5 ) · 6x / 5
= 4 · 6x / 5 · 5 = 24x / 25
24x / 25 = 1248 lei
x = 25 · 1248 / 24 = 25 · 52 lei = 1300 lei