#1**0 **

Assuming Point I is in the interior of angle GHU....because there isn't a diagram or any confirmation.

The angle addition postulate states that if Point D is in the interior of Angle ABC, then Angle ABD + Angle CBD = Angle ABC.

Applying this to your problem, gives: (12x+1) + (-11+8x) = 60

Combine like terms: 20x-10=60

Solve for x: 20x=70

**x=7/2, or 3.5**

You can check your work by plugging x in for the angles, and seeing if sum of the angles equals 60 or not.

12(3.5)+1=43

-11+8(3.5)=17

43+17=60, meaning that its correct.

caramel Jan 16, 2022