Question

un ciclist a parcurs un traseu in trei zile.In prima zi a parcurs o cincime din traseu ,a doua zi a parcurs doua cincimi din rest iar a treia zi inca 20 km .Aflati lungimea traseului

Answer 1

x= traseul

I zi ........... 1/5 × x

II zi ..........2/5 × ( x - 1/5 × x)

III zi ......... 20 km

x = 1/5 × x + 2/5 × ( x - 1/5 × x) + 20

x = x/5 + 2/5 × ( x - x/5 ) +20

x = x/5 + 2x/5 - 2x/25 + 20

x = 3x/5 -2x/25 + 20

-20 = 15x/25 - 2x/25 -x

-20 = 13x/25 -25x/25

-20 = -12x/25

-12x = -20 × 25

-12x = -500

x = 125/3