Urgent please help..

Answer:
x = 12
Step-by-step explanation:
Here, we want to find the value of x
To do this, we use one of the circle tangent relationships
we have this as:
8^2= 4(4 +x)
8^2 = 16 + 4x
64 = 16 + 4x
64-16 = 4x
4x = 48
x = 48/4
x = 12