Explanation:
For first you can do like this:
Angle T you can get:
180°-(25°+55°)
180°-80°
100° Angle T
And Angle X is
180°- 100°= 80°
Second one:
First you need to find angle S and you do it like this:
180°-156°= 24°
Then angle R is:
180°-(24°+96°)= 180°-120°=60°
Hope this helps.