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The sum of 2 numbers is 7, the sum of their cubes is 133. Find the sum of their squares |
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Answer» Answer: Step-by-step explanation: LET two number be a and b, According to question,we GET, a+b=7 a 3 +b 3 =133 Now, (a+b) 3 =a 3 +b 3 +3ab(a+b) =>7 3 =133+3ab(7) => 21 343−133
=AB =>ab= 21 210
=>ab=10 Now, (a+b) =a 2 +b 2 +2ab =>7 2 =a 2 +b 2 +2(10) =>a 2 +b 2 =49−20 =>a 2 +b 2 =29 |
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