The two red points are lying on the line
let us call them A( on y axis) and B ( in third quadrant )
Co ordinates of A can be seen easily : 0 movement on x axis and +2 movement on y axis so co ordinates of A ( 0,2)
Co ordinates of B: -4 movement on x axis and -6 movement on y axis so co ordinates are ( -4,-6)
Let us say x1 y1 = (0,2) and x2 y2 = ( -4,-6)
first we find slope of this line : ( y2 - y1) divide by ( x2-x1)
: ( -6 -2 ) divide by ( -4 -0)=
: (-8) divide by ( -4 )
Slope m = +2
Now equation of line should be Y- y1 = m( X-x1)
Y - 2 = +2( X- 0)
Y - 2 = 2X
Y = 2X+ 2
This is the required equation of the line