Answer:
The slope of a line that is perpendicular to the line whose equation is
is
Step-by-step explanation:
Given : Equation 
To find : What is the slope of a line that is perpendicular to the line whose equation is given?
Solution :
First we find the slope of the given line,
The general slope form of line is
where m is the slope of the line and b is the y-intercept.
Re-write the given equation into general form,

Take 5x to another side,

Divide both side by 8,

On comparing with general form,
The slope of the line is 
We know,
When two line are perpendicular one slope is negative reciprocal of another.
If the slope of line is
Then the slope of perpendicular line on this line is
Therefore, The slope of a line that is perpendicular to the line whose equation is
is