Answer:
1. x=37
2. x= 50
Explanation:
Add up the two angles you already have, 43+100 and then subtract from 180.
180-143= 37
Do the same thing for number 2.
Add up 99+31, which is 130
The subtract from 180
180-130=50
The equation for triangles is x + (the angle measures) = 180
Hope this helps <3