D=4Step-by-step explanation:
 
        
             
        
        
        
Answer:
The answer to your question is
                        Number of stickers = number of days + 3
Step-by-step explanation:
- To find the equation of the line that represents the situation, first, find the slope.
Slope = m = 
              m = 
 - Find the equation of the line
                       y - y1 = m(x - x1)
                       y - 4 = 1(x - 1)
                       y - 4 = x - 1
                            y = x - 1 + 4
                            y = x + 3
y = number of stickers
x = days
                       Number of stickers = number of days + 3