Which of the following expressions CANNOT be factorised using the difference of two squares method?

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Question

Which of the following expressions CANNOT be factorised using the difference of two squares method?

Accepted Answer

m² + 25 — Award 1 mark for recognising that the sum of two squares cannot be factorised using real numbers. D is incorrect — this is (x − 4)(x + 4). A is incorrect — this is (2y − 3)(2y + 3). C is incorrect — this is (7 − n)(7 + n).

Answer

x² − 16

Answer

49 − n²

Answer

m² + 25

Answer

4y² − 9

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