Respuesta :

9514 1404 393

Answer:

  (d)  8

Step-by-step explanation:

Corresponding sides are proportional.

  ED/EG = EC/EF

  (6x +3)/17 = (8x -1)/21

  21(6x +3) = 17(8x -1)

  126x +63 = 136x -17

  80 = 10x . . . . . . . . . . . add 17-126x

  8 = x . . . . . . . . . . divide by 10