Question

If x+y+1 =0 , prove that x cube +y cube
+ 1 =3xy

Answer 1

Answer:

Step-by-step explanation:

As x+y+1=0

So, x+y = -1

Cubing both side , we get

(x + y ) ^3 = -1

x^3 + y^3 + 3xy (x+y) = -1

x^3 + y^3 + 3xy (-1) ● see the second line● = -1

x^3 + y^3 +1 -3xy =0

x^3 + y^3 +1 = 3xy

HP