Question 253289
Given two points (0,0) & (4,2) you need to define the slope of the line through these two points or the slope (m).
Slope (m)=(y2-y1)/(x2-x1)=(2-0)/(4-0)=2/4=1/2=.5
Using the line equation Y=mX+b, with the second set of points (2,4) & the slope (m)=.5 we find the y intercept (b).
2=.5*4+b
2=2+b
b=2-2
b=0 the y intercept.
Y=.5X+0
Graphing this line we have the rise (Y=2) & the run (X=4).
{{{ graph( 300, 200, -6, 5, -10, 10, y = .5x) }}} (graph 300x200 pixels, x from -6 to 5, y from -10 to 10, y = .5x).