Respuesta :

Answer:

x have to be equal to 3

Step-by-step explanation:

Mathematically, when two triangles are similar, the ratios of their corresponding sides are equal

Thus, we have it that;

AB/AC = DE/DF

9/3(x-1) = 6/x + 1

9(x + 1) = 6(3(x-1))

9x + 9 = 18x - 18

18x-9x = 9 + 18

9x = 27

x = 27/9

x = 3