Respuesta :

Answer:

7

Step-by-step explanation:

Because these two triangles share an angle and their corresponding sides are parallel, they are similar.

So, we can set up a proportion relating corresponding sides:

10 / (10 + 8) = (3x - 6) / (3x - 6 + 12)

10/18 = (3x - 6) / (3x + 6)

Cross-multiply:

18 * (3x - 6) = 10 * (3x + 6)

54x - 108 = 30x + 60

24x = 168

x = 168/24 = 7

The answer is 7.

~ an aesthetics lover