Answer:
Slope of a line parallel is -5/9.
Slope of a line perpendicular is 9/5.
Explanation:
5x + 9y = 1
To find the slope of this line we convert the equation to slope-intercept form ( y = mx + c where m is the slope).
9y = -5x + 1
y = -5/9 x + 1/9
So its slope (m) is -5/9.
So slope of a line parallel to this is also -5/9.
Slope of a line perpendicular = -1 / -5/9
= 9/5.