Answer:
11
Explanation:
The two labelled angles are complementary, which means they add up to 90 degrees. (Note: the little "square" in the corner of an angle always means that it's 90 degrees)
Here, we have 35 and 5x, and their sum is 90 so:
35 + 5x = 90
5x = 90 - 35 = 55
x = 55/5 = 11
Thus, the answer is 11.
Hope this helps!