Răspuns :
x- pretul cartii dinainte de reducere
x-20/100x(reducerea)=96
x(1-20/100)=96
80/100x=96
x=96x10/8
x=120 lei
x-20/100x(reducerea)=96
x(1-20/100)=96
80/100x=96
x=96x10/8
x=120 lei