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A number plus its reversal (Posted on 2018-12-03)

List all two digit numbers that if reversed and added to the original number create a perfect square.

See The Solution Submitted by Ady TZIDON

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Corrected Solution

| Comment 2 of 6 |

Let the digits be a and b.

Then (10a+b) + (10b+a) = 11(a+b) must be a perfect square.

This is the case if and only if a + b = 11.

So the solution is 29, 38, 47, 56, 65, 74, 83 and 92.

Posted by Steve Herman on 2018-12-03 19:49:35

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