Question

If x-y = 2 , then the volue of x³-y³ -6xy is
(a) 7
(b) 8
(c) 9
(d) 10
Give me the write answer ​

Answer 1

Answer:

(b)

Solution:

(x-y)³ = x³ - y³ -3xy(x-y)

Putting the value of (x-y) = 2,

2³ = x³ - y³ -3xy(2)

or, 8 = x³ - y³ -6xy

or,  x³ - y³ -6xy  = 8