Question

If x = a + b, y = a + b , z = a + b , where , are non-real cube roots of unity, then xyz is equal to

Answer 1

xyz= (a+b)(a+b)(a+b)
a(a+b)+b(a+b) (xy)
a²+2ab+b²
a(a²+2ab+b²)+b(a²+2ab+b²)
a³+2a²b+ab²+ab²+2a²b+b³
=. a³+b³+4a²b+2ab²