Answer 1

ω is a complex cube root of unity.

∴ ω³ = 1 and 1 + ω + ω² = 0

∴ ω + ω² = – 1, 1 + ω = – ω² and 1 + ω² = – ω

(2 – ω)(2 – ω²) = 7

= 4 – 2ω² – 2ω + ω³

= 4 – 2(ω² + ω) + ω³

= 4 – 2(– 1) + 1

= 4 + 2 + 1

= 7