Question

what is the difference between y=2x, y=2x+4, and y=2x+6

Answer 1

See: an equation having the form :

y = mx + c represents a line with slope m and y - intercept c.



Now lines having same value of m are parallel lines.

Answer 2

Now, the given lines all have same m (=2) and thus are parallel with different y - intercepts.