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Un automobil a parcurs o distanta astfel:in prima zi a parcurs 35% din drum,a doua zi 20% din rest,iar a treia zi restul de 624 km.Aflati distanta totala.

Răspuns :

In prima zi 35x/100=7x/20 =>rest 13x/20
In a doua zi 20/100 · 13x/20
                    1/5 · 13x/20 = 13x/100
In a treia zi 624 km
7x/20 + 13x/100 + 624 = x
35x+13x+62400=100x
62400=100x-48x
62400=52x
x=1200 km
Notam distanta totala cu x
in prima zi a parcurs 35x/100
a doua zi a parcurs 20/100( x- 35x/100)=20/100(65x/100)=13x/100
a treia zi a parcurs 624 km
x-35x/100 - 13x/100=624       aducem la acelasi numitor comun, 100
100x-35x-13x=62400
52x=62400
x=1200