Answer:
x = 12
Explanation:
The attached figure shows the measures of the angles. Here, line a is parallel to line b.
Given that,
m∠3 = 128 and m∠6 = (10x + 8)
We need to find the value of x.
Here,
(alternate interior angles)
So,

So, the value of x is 12. Hence, the correct option is (D).