Answer:
one unit
Explanation:
the best way to visual this is to convert the standard form equations into slope form (y = mx + b), and compare the y-intercepts
2x + 4y = 8
4y = -2x + 8
y = (-2/4)x + 2
y = (-1/2)x + 2
3x + 6y = 18
6y = -3x + 18
y = (-3/6)x + 3
y = (-1/2)x + 3
since 2 and 3 are only one unit away, the distance is one unit.