Hey there! :D
The congruence marks on the trapezoid make the angles congruent. This makes opposite angles supplementary. (Because all the angles in a trapezoid add up to 360 degrees)
12x-31+6x-5= 180
18x-36= 180
Add 36 to both sides. 
18x= 216 
Divide both sides by 18. 
x= 12
You can just plug that in to find m<H. 
6x-5
6(12)-5
72-5
m<H= 67
I hope this helps!
~kaikers
        
             
        
        
        
First one is 14
Second one is 45
Third one is 43
Fourth one is 40
        
                    
             
        
        
        
<h3>
Answer:  72 words per minute</h3>
Work Shown:
1 hour = 60 min
2 hours = 120 min (multiplied both sides by 2)
2 hours + 30 min = 120 min + 30 min = 150 min
speed = (number of words typed)/(time taken)
speed = (10800 words)/(150 min)
speed = (10800/150) words per minute
speed = 72 words per minute
 
        
        
        

Now plug the x value into 9x + 2

Hope that helps!