Respuesta :

X=12 because the ABC triangle is doubled the values

The similarity ratio of two similar triangles is equal to the ratio of their corresponding sides :

Similarity ratio = BA / GF = BC / GH = CA / HF

Similarity ratio = 18 / 9 = 14 / 7 = x / 6

x / 6 = 2

multiple sides by 6

6 × x / 6 = 6 × 2

simplification

x = 12