### Wednesday, April 20, 2016

#### Examples of Sum of products equal to sum of products

For all integers A, B, C, D, the sum of products, (A-B)*(C+D) + (B-D)*(A+C) is equal to the sum of products (A+B)*(C-D) + (A-C)*(B+D) Example 1: Let A = 11, B = 7, C = 5, D = 3 (A-B)*(C+D) + (B-D)*(A+C) = (11-7)*(5+3) + (7-3)*(11+5) = 4*8 + 4*16 = 32 + 64 = 96 (A+B)*(C-D) + (A-C)*(B+D) =...

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