Question

The coordinates of A, B, and C in the diagram are A(p,4), B(6,1), and C(9,q). Which equation correctly relates p and q?

Hint: Since AB is perpendicular to BC , the slope of AB x the slope of BC = -1.

This is a PLATO math question, will give 15 pts

attached is the diagram

answer choices:


A.
p − q = 7
B.
q − p = 7
C.
-q − p = 7
D.
p + q = 7

Answer 1

D. p + q = 7

Explanation:

Just did this quiz on edmentum :P

Answer 2

D. p + q = 7

Explanation:

The slope of AB is ...

slope AB = (1 -4)/(6 -p) = 3/(p -6)

The slope of BC is ...

slope BC = (q -1)/(9 -6) = (q -1)/3

The product of these is -1, so we have ...

(slope AB)·(slope BC) = -1 = (3/(p -6))·((q -1)/3)

Multiplying by q -1 gives ...

-(q -1) = p -6 . . . . . . the factors of 3 in numerator and denominator cancel

1 = p + q -6 . . . . . . add q

7 = p + q . . . . . . . . add 6 . . . . matches choice D