posted by caduceus .
What is the slope of the line that is perpendicular to the line represented by the equation below?
4x - 5y = -1
is this c or d? reiny, i used what you said, but since this is subtraction i was unsure of whether or not it would be negative or not.
5 y = 4 x + 1
y = (4/5) x + 1/5
slope = 4/5
so slope of perpendicular = -5/4