there is no factorization of y^2 -2y +35 in real numbers
Thomasina correctly determined two factors of 35 that differ by 2, but that is not what is needed here. For this problem, she needs two factors of 35 that have a sum of 2.* (There aren't any real-number factors that meet that condition.)
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The factorization in complex numbers would be ...
= (y -1 -i√34)(y -1 +i√34)
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* Technically, she needs two factors of 35 with a sum of -2. Both factors would have to be negative.
