Question 1129772
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I don't know of any easy way to find the answer algebraically....<br>
You can of course ignore the answer from the other tutor.  It was the first answer on this site from him, so it was probably just some joker who thought it would be fun to respond to your question with a useless answer.<br>
Obviously there are not 331 positive integers less than 289....<br>
You can use an excel spreadsheet or the table function of a graphing calculator to divide the expression by 289 for every integer from 1 to 288; you will find it is divisible by 4 positive integers less than 289: 42, 241, 285, and 287.