The line x = -10, is an example of an undefined line. It does not pass the vertical line test and each element of the domain is not paired with a unique (one and only one) element of the range. Remember that no two ordered pairs in a function have the same first element.
To find the line parallel to the line given line, we need to use the x-value in the given ordered pair, which will create the parallel line.
Therefore, the line parallel to the line x = -10 is x = -4.
