Let every line = 1 unit:
Point C is located at (0,0)
Point D is located at (7, 12)
The slope is the change in Y over the change in X:
Slope = 12-0 / 7-0 = 12/7
The equation of the line from C to D using mx +b:
m = slope, which we already calculated as 12/7
To solve for b, replace m with 12/7 to get
y=12/7x +b
replace x with 0 ( from point C )
y = 12/7(0) +b
Replace y with 0 (also from point C)
0 = 12/7(0)+b
Solve for b:
b = 0
The equation becomes y= 12/7x
The Domain is the X values, which range from A to E, -12 to 13
Which is written as (-12,13) or -12≤x≤13
The range is the Y values, which range from A to D, 0 , 12
Which is written as (0,12) or 0≤y≤12