Question

Cineva a cheltuit o suma de bani astefel:in prima zi a cheltuit 3/8 din suma ,a doua zi 4/15 din rest ramanandu-i necheltuiti 55 lei .ce suma a avut?
Repedee va rog
Dau coroanaaa

Answer 1

[tex]\text{Notez suma initiala cu x:}\\ \dfrac{3x}{8}+\dfrac{4}{15}\left(x-\dfrac{3x}{8}\right)+55=x\\ \dfrac{3x}{8}+\dfrac{4}{15}\cdot \dfrac{5x}{8}+55=x\\ \dfrac{3x}{8}+\dfrac{x}{6}+55=x|\cdot 24\\ 9x+4x+1320=24x\\ 13x+1320=24x\\ 11x=1320\\ x=120\ lei[/tex]