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Algebra Difficulty 5.0 AIME, harder Find the answer
Real numbers a,b,c satisfy the equations a+b+c=26,1/a+1/b+1/c=28. Find the value of ba+cb+ac+ca+bc+ab
A number or a short expression. Spacing and $ signs are ignored.
Solution
Multiplying the two given equations gives aa+ba+ca+ab+bb+cb+ac+bc+cc=26⋅28=728 and subtracting 3 from both sides gives the answer, 725.
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