Question
Question: If \(a , b , c\) are in A.P., then \(( a + 2 b - c )\) \(( 2 b + c - a )\) \(( c + a - b )\) equ...
If a,b,c are in A.P., then (a+2b−c) (2b+c−a) (c+a−b) equals.
A
21abc
B
abc
C
2 abc
D
4 abc
Answer
4 abc
Explanation
Solution
(a+2b−c)(2b+c−a)(c+a−b)
=(a+a+c−c)(a+c+c−a)(2b−b) =4abc
(∵a,b,c are in A.P., ∴2b=a+c ) .