1.

If ab + bc + ca = 8 and a2 + b2 + c2 = 20, then a possible value of 1/2 × (a + b + c)[(a – b)2 + (b – c)2 + (c – a)2] is:

A. 72
B. 56
C. 820
D. 84
Answer» B. 56


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