## Calculus with Applications (10th Edition)

$$-\frac{1}{4}$$
The equation of the line given by $$8x=2y-5$$ can be rewritten as $$2y=8x+5$$ or $$y=4x+\frac{5}{2}$$ The equation of a line in slope-intercept form is $$y=mx+b$$ where $m$ is the slope and $b$ is the y-intercept. For this line the slope is $$m=4$$ For a line perpendicular to the original, the slope is the negative reciprocal $$m=-\frac{1}{4}$$