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Sum of powers (Posted on 2015-11-18)

Given a+b=1 & a^2+b^2 =25,

Find a^4+b^4, without solving for a and b.

No Solution Yet Submitted by Ady TZIDON

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A little more direct....

Comment 3 of 3 |

Start with the identity:

a^4+b^4 = (a+b)^2*(a^2+b^2) + [(a^2+b^2)^2 - (a+b)^4]/2

Then substitute:

a^4+b^4 = 1^2*25 + [25^2 - 1^4]/2 = 337

Posted by Brian Smith on 2016-07-13 09:57:02

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