Explanation:
Put both of the equations into y = mx + b form to compare them
m = slope if they have the same slope they are parallel and do not intersect
b = y axis intercept
if m and b are equal in each of the equations , they are the same line
2x+y = 0 ======> y = - 2x + 0
2y = -4x + 6 ====> y = - 2x + 3
The both have the same slope = -2 so they are parallel
but they have different b values so they are not the same lines
No intersection means no solution : parallel lines do not intersect