Mathematics > Standard Multiple Choice
Read the following SAT test question and then click on a button to select your answer.
In the 
-plane, line 
passes through the points 
and 
. Line 
is perpendicular to line . What is the slope of line 
?
(A) 
(B) 
(C) 
(D) 
(E) 
Explanation
Line passes through the points 
and 
, so the slope of line is equal to 
. Lines and 
are perpendicular, so the slope of line 
is equal to the negative reciprocal of the slope of line . Therefore, the slope of line 
is 
.