Question

the equation of line k is y=1/5x-1/8. what equation of the line that is perpendicular to line k and passes through (0,0)

Answer 1

The slope of a perpendicular line is the negative reciprocal of the normal slope.  For example, 3/7 would become -7/3.  

Because the slope of this line is 1/5, the slope of a line that is perpendicular to it is -5.

Now, to find the equation of the line, we need to find the y intercept.  Since the line passes through (0,0), that is the y intercept.  Now, we can make the equation of the line.

y = -5x