Discussion: This student makes use of the unique factorization to solve this problem. All possible pairs of integers whose product is 30 are enumerated and these are the possibilities for x-y and x+y. This leads to two simple linear equations in each case which yields unique solutions which are not integers. This problem would have better if it had asked the student to generalize and conclude that an even number is the difference of two squares if and only if it is a multiple of 4.

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