How do you figure something like this out?

What is the slope of a line perpendicular to the line with equation y = 4x + 5?How do you figure something like this out?
Perpendicular lines have negative reciprocal slopes. The slope is the number BEFORE the x. Therefore, in this case...it's 4. The reciprocal of 4 is 1/4 and you want to make it -.





Answer = -1/4How do you figure something like this out?
Graph the line. Find the line at a 90 degree angle from it. Solve for the slope of that line.