Practice!

Sample Problem

When put on a coordinate plane, Main Street has the equation y = -x – 4. Park Street is perpendicular to Main Street and goes through the point (3, -5). Write the equation for Park Street in slope-intercept form.

y = x +

Solution

Since Park Street is perpendicular to Main Street, it has a slope of 3.

Now, we plug in the point we know on Park Street, then solve for b. -5 = 3(3) + b; b = -5-9=-14.

So the equation for Park Street is y = 3x – 14.