Question

Andrei cheltuie in prima zi un sefrt si inca 5 lei, in a doua zi 40% din rest, ramanand cu 60 lei. Care este suma initiala ?

Answer 1

x-suma totala

I:x/4+5
II:40% din rest
rest nou=60 lei

x-(x/4+5)
=x-(x+20)/4
=(4x-x-20)/4
=(3x-20)/4
II:40*(3x-20)/400=(3x-20)/10
     ↓
x/4+5+(3x-20)/10+60=x
.
.
.
x=140 lei