The expression (a + b − c)3 + (a − b + c)3 − 8a3 is equal to: |
6a(a − b + c)(c − a − b) 3a(a + b − c)(a − b + c) 6a(a + b − c)(a − b + c) 3a(a − b + c)(c − a − b) |
6a(a − b + c)(c − a − b) |
Let a = b = c = 1 (a + b – c)3 + (a – b + c)3 – 8a3 = 1 + 1 – 8 = (-6) Checking option 3rd. 6a(a – b + c) (c – a – b) = 6 × 1 × (-1) = (-6) Satisfied. So the value of (a + b – c)3 + (a – b + c)3 – 8a3 = 6a(a – b + c) (c – a – b) |