Step 1 :The given line equation is \(-2x - 9y = 5\).
Step 2 :The slope of a line given by the equation \(ax + by = c\) is \(-\frac{a}{b}\). So, the slope of the given line is \(-\frac{-2}{-9} = \frac{2}{9}\).
Step 3 :A line parallel to another line will have the same slope. So, the slope of the line parallel to the given line is also \(\frac{2}{9}\).
Step 4 :The equation of a line in slope-intercept form is \(y = mx + c\), where \(m\) is the slope and \(c\) is the y-intercept. We can find the y-intercept by substituting the coordinates of the given point and the slope into this equation.
Step 5 :The slope of a line perpendicular to another line is the negative reciprocal of the original line's slope. So, the slope of the line perpendicular to the given line is \(-\frac{9}{2}\).
Step 6 :We can find the equation of the line perpendicular to the given line in the same way as we did for the parallel line.
Step 7 :The equation of the line that is parallel to the line \(-2 x-9 y=5\) and passes through the point \((-8,6)\) is \(y = \frac{2}{9}x + \boxed{7.78}\) (rounded to two decimal places).
Step 8 :The equation of the line that is perpendicular to the line \(-2 x-9 y=5\) and passes through the point \((-8,6)\) is \(y = -\frac{9}{2}x - \boxed{30}\).