Question

daca un obiect se va scumpi cu 20% el va costa 48 lei .
cat a costat inainte?

Answer 1

Fie x pretul initial al obiectului.
x+20/100x=48
x+1/5x=48
x(1+1/5)=48
x(5/5+1/5)=48
x(6/5)=48
x=48/ 6/5
x=48* 5/6
x=40lei

Answer 2

x+20%x=48     $x+\frac{20}{100}x=48$   (Aducem la acelasi numitor si facem adunarea...)  $\frac{120}{100}x=48$$x= \frac{48*100}{120}$ x=$\frac{48+10}{12} =4*10=40$