If you divide the first by 2, you get the second equation.
This means that both equations plot an identical line (they lie on top of each other /also known as "coincide"). This means, that there are infinitely many solutions.
In 2D (x-y plane for example), straight lines can have no solutions if they have the same gradient/slope/ they are parallel and different y-intercepts, because they will never cross.
Here, they have same gradient and y-intercept so all points on the line are valid solutions to the equation
