Question

20) If x/y+y/x = 1 then the value of
x^3-y^3 is *
O a)1
O B)-1
OC)O
O D)1/2​

Answer 1

Answer :

c) 0

Explain :

x/y + y/x = 1

(x^2 + y^2) / xy = 1

(x^2 + y^2) = xy

x^2 + y^2 - xy = 0

therefore x^3 - y^3 = (x+y) (x^2 - xy + y^2 )

= (x + y ) ( 0 )

= 0.