Question

vlad cheltuieste 25% dintr-o suma de bani, apoi trei cincimi din rest, ramandu-i 240 lei. ce suma a avut initial Vlad?

Answer 1

x= suma initiala

$\dfrac{25}{100}\cdot x+\dfrac35\cdot\dfrac{75}{100}\cdot x+240=x$

$\dfrac x4+\dfrac{9x}{20}+240=x$

$14x+4800=20x$

$6x=4800$

$x=800\ lei$