SOLUTION: If a+b=9 and a^3+b^3=351, find the numerical value of ab

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Question 344685: If a+b=9 and a^3+b^3=351, find the numerical value of ab
Answer by Jk22(389) About Me  (Show Source):
You can put this solution on YOUR website!
(a+b)^3=a^3+3a^2b+3ab^2+b^3=351+3ab(a+b)=351+3ab*9=9^3=81*9=729

hence 27ab=729-351=378

ab=126/9=42/3=14