Răspuns :
fie X, pretul initial
atunci;
x-10x/100=54
100x/100-10x/100=54
90x/100=54
9x/10=54
9x=540
x=540:9
x=60
atunci;
x-10x/100=54
100x/100-10x/100=54
90x/100=54
9x/10=54
9x=540
x=540:9
x=60