Question

Un automobil parcurge un traseu in 3 etape.in prima etapa 2 supra5 din lungimea drumului ,in a doua 1supra3 din rest iar in a treia 74,8km.Aflati lungimea traseului?

Answer 1

x= 2/5x + 1/3(x- 2/5x)+ 74,8
x= 2/5x + 1/3x - 2/15x + 74,8
x= 6/15x + 5/15x- 2/15x + 74,8
x = 9/15x +74,8
x - 9/15x = 74,8
15/15x - 9/15x = 74,8
6/15x = 74,8
6x = 74,8 * 15
6x = 1122
x = 1122/6 = 187

Answer 2

1)  2x /5   ;   x-2x /5 =5x =5-2x /5 =3x /5  ramas  ( x=drumul )
2)1/3*3x/5 =3x/15=x/5
3) 74.8  km
2x/5+x/5 +74.8 =x  ;  numitor  5
2x+x+374 =5x
2x+x-5x = -374
2x =374
x =187 km
verif ;   2*187/5  +187/5  +74.8 =
                     74.8 +37.4 +74.8 =187 km