Question

Consider a,b,c : real numbers. $X=\frac{a+b}{a-b},Y=\frac{b+c}{b-c},Z=\frac{c+a}{c-a}$ . What is the value of XY+YZ+XZ?

• A. 1
• B. 2
• C. 1/2
• D. none of these

Answer 1

The correct option is D none of these

Answer =e

Assume a=1, b=2, c=3

X=-3Y=-5Z=2

XY+YZ+XZ = 15-10-6 = -1

Assume a=2,b=3 and c=4

X= -5Y= -7Z= 3

XY+YZ+XZ= 35-21-15= -1

Hence answer =( e)