Answer:
y equals three sevenths times x plus 3
Step-by-step explanation:
Given the information: 
- points going up from about zero comma negative 3 
<=> Let A (x1, y1) =  (0, -3) 
- to the right to about 7 comma zero
<=> Let B (x2, y2) = (7, 0)
As we know, the line of best fit is a linear equation that represent the data with the standard form: 
y = mx + b where: 
- m is the slope 
- b is the the y-intercept when x = 0 
For a line that goes trough the points (x1, y1) and (x2, y2), the slope is
m =  
 
In this situation, we have: 
m =  =
 =  
  
=> y =  x + b.
  x + b. 
Because the line goes through A (0, 3) 
=> 3 =  *0 + b
  *0 + b 
<=> b =3
=> y =  x +  3
  x +  3
So we choose y equals three sevenths times x plus 3