Question

The lines below areperpendicular. If the green line has a slope of -1/4 what is

the slope of the red line? Enter your answer as an integer or a fraction in
lowest terms.

Answer 1

Answer: 4

Let's say line A and B are perpendicular lines.

If the slope of line A is -1/4, then the slope of line B is 4/1 = 4.

Note how the two slopes multiply to -1.

Your textbook might use the term "negative reciprocal" or "opposite reciprocal" when going from -1/4 to 4/1. We basically flip the fraction and flip the sign.