Question

un elev a cheltuit o suma de bani economisita, astfel:dupa ce in prima zi a cheltuit 5/8 din suma si a doua zi a cheltuit 40% din suma ramasa, elevului i au mai ramas 72 de lei . calculati suma de bani economisita de elev. 100 de puncte repede plsssss

Answer 1

Răspuns:

x=suma de bani

5x/8 a cheltuit in prima zi

⁸⁾x-5x/8=(8x-5x)/8=3x/8 rest

3x/8·40/100=3x/8·2/5=6x/40 a cheltuit a2a zi

⁵⁾5x/8+6x/40+⁴⁰⁾72=⁴⁰⁾x

25x+6x+2880=40x

2880=40x-31x

x=2880:9

x=320 lei suma de bani economisita