Problem
What is an equation of the line that passes through the point \( (5,-8) \) and is perpendicular to the line \( 5 x-4 y=16 ? \)
Solution
Step 1 ：1. Find the slope of given line: $\frac{5}{4}$
Step 2 ：2. Find the slope of perpendicular line: $-\frac{4}{5}$
Step 3 ：3. Use point-slope form: $y - (-8) = -\frac{4}{5}(x-5)$
