Answer:
1. x = 21
2. m∡ABC =  51°
Step-by-step explanation:
First problem, solve for x
the sum of inside angles of a triangle is 180
also the supplementary angle for L = 180 - 100 is 80° 
now you can add all angles
80 + 2x - 11 + 2x + 27 = 180
4x + 96 = 180
4x = 84
x = 21
Second problem, solve for m∡ABC
the sum of inside angles of a triangle is 180
also the supplementary angle for C = 180 - 148 is 32° 
now you can add all angles
31 + 2x - 15 + x - 5 = 180
3x + 12 = 180
3x = 168
x= 56, 
now solve for  m∡ABC = (x - 5)° = (56 - 5)° = 51°
 
        
                    
             
        
        
        
It decreased $7 in the last 2 days
        
             
        
        
        
Taken time is from 11.00 am to 2.30 pm (14.30) = 14.30 - 11 = 3.30 hours
We know that D = S* T (D - distance, S - speed , T- time)
So, 
 
 
        
        
        
Slope is mx is that makes sense