9) Here, Two angles are unknown without any relation not even a variable.
So, we could calculate the sum of that two unknown angles only,not their individual magnitude.
It would be: 50 + 152 + missing angles = 360
m.a = 360 - 202
m.a = 158
In short, Sum of two Unknown angles would be 158
10) Here, ABCD is a Quadrilateral, so their adjacent side would make a linear pair equation, means their sum would be equal to 180
So, ∠1 + ∠2 = 180
Hope this helps!