Step-by-step explanation:
the slope of a line is always the factor of x in the equation. in our case here : 5/8.
the slope is the y/x ratio indicating how many units y changes, when x changes by a certain amount of units (e.g. when going from one point on the line to another).
the perpendicular slope (crosses the original line in a right angle = 90 degrees) turns x and y upside-down and flips the sign.
so, in our case, it is -8/5.
