Question

Two lines are perpendicular. If one line has a slope of 1/21 , what is the slope of the other line?

A. -1/21
B. 1/21
C. 21
D. -21

Answer 1

-21

Answer 2

-Snipped-

Answer 3

Perpendicular lines have slopes that are negative reciprocals. That isa fancy mathematical way of saying that if you have the slope of one line and you want the slope of a perpendicular to that line, filp the fraction and change the sign.

Answer 4

1/21
Filp it:
21/1 = 21
Change sign:
-21

Answer 5

Flip the sign and negate it.
1/21 becomes -1/21.Now flip. Becomes -21.