Answer:
4
Step-by-step explanation:
We know that this is a supplementary angle, which means the sum of two angles is 180 degrees.
The Equation would then be:
140+10x=180
All you need to do is solve for x.
140+10x=180
-140 -140 (Subtract 140 from both sides)
10x=40 (Divide by 10)
x=4
