a)
Notam suma initiala cu x
Prima zi:
[tex]\frac{40x}{100}[/tex]
Rest:
[tex]x-\frac{40x}{100} =\frac{60x}{100}[/tex]
A doua zi:
[tex]\frac{60x}{100} \cdot \frac{60}{100}= \frac{36x}{100}[/tex]
Rest:
[tex]\frac{60x}{100}-\frac{36x}{100}=\frac{24x}{100}[/tex]
A treia zi:
[tex]\frac{40x}{100}-128=\frac{24x}{100}[/tex]
Aducem la acelasi numitor comun 100 si obtinem:
40x-12800=24x
16x=12 800
x=800 lei
In a treia zi a cheltuit: [tex]\frac{40\cdot 800}{100}-128= 192\ lei[/tex]
In prima zi a cheltuit: [tex]\frac{40\cdot 800}{100}=320\ lei[/tex]
[tex]\frac{192}{320} \cdot 100=60\%[/tex]
b)
In a doua zi a cheltuit: [tex]\frac{36\cdot 800}{100}=288\ lei[/tex]
Un alt exercitiu asemanator gasesti aici: https://brainly.ro/tema/7073033
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