Respuesta :

Answer:

Step-by-step explanation:

this is a similar triangle,  so the side that is 6 and 18 will have the same ratio as the side 4 and x,  then

6/18 = 4 / x

x = 4 * 18/6

x = 2 * 18 / 3

x = 36 /3

x = 12

nice :)