A•B + B•C = (A+C)•B = -B•B = -1 B•C + C•A = (A+B)•C = -C•C = -4 A•B + B•C = (B+C)•A = -A•A = -3 add them all up and you have 2(A•B + B•C + C•A) = -8 A•B + B•C + C•A = -4
You can ask a new question or answer this question.