What represents a line that is parallel to x-4y=16 ???

X - 4y + b = 0 answer

The equation of a line parallel to a line ax + by + c = 0 is ax + by + d = 0.
In other words, the equation of two parallel lines differ by a constant.
Therefore, if the equation of the line is: x - 4y - 16 = 0, then the equation of the line parallel to this should be: x - 4y + d = 0.
If we are given a point, say (x₁, y₁) on the line then we can substitute this point on the equation to determine the value of 'd'.