The canonical form for the line equation ( linear function) is given by:
y = mx + b
where m is the slope of the line and b is the y-coordinate of the y-intercept of the line. If we solve for b, then the above equation can be written as:
y-mx = b
taking into account the above, in our case we have:
y+2x = b EQUATION 1
where -2 is the slope of the line (negative slope). To find the complete equation, we must find b, replacing in the previous equation a point (x, y) belonging to the line. For example (x,y) =(0,2). Then we have:
2 + 2(0) = b
that is:
2 + 0 = b
that is
2 = b
Replacing the above in equation 1, we have that the line equation would be:
y + 2x = 2
