The answer would be 10.
6 + 5 = 11
11 x 9 = 99
This means 9(6+5) = 99
99 - 89 = 10
Are these angles measurements or triangles or just variables?
Answer:

Step-by-step explanation:

Find the sharing components:
<=> 
Apply the inverse of associative property:
<=> 
Identify two square components inside the parenthesis:
<=> 
Factorize:
<=> 
=> Option D is correct
Hope this helps!
:)