Answer:
6
Explanation:
According to secant-secant theorem,
(PB)(PA)=(PD)(PC)
(7)(12)=(PD)(14)
NOW
84/14 = PD
PD = 6
Swapping rows alters the sign of the determinant:

Multiplying a single row by a scalar scales the determinant by the same amount:

Then

Answer:
b
Step-by-step explanation:
What is the equation ? Is there a picture to the question.