Expression = 2b2c2+2c2a2 + 2a2b2–a4–b4–c4 = 4b2c2 – (2b2c2–2c2a2–2a2b2+a4+b4+c4) = (2bc)2 – (a2–b2–c2)2 = (2bc + a2–b2–c2) (2bc – a2+b2+c2) = (a2–(b2+c2–2bc))(b2+c2+2bc–a2) = (a2–(b–c)2)((b+c)2–a2) = (a – b + c) (a + b – c) (a + b + c) (b + c – a) If a + b – c = 0, ∴ Expression = 0.