Julian Det De Villa Zapanta's answer to Dunelm's Secondary 3 A Maths Singapore question.

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Julian Det De Villa Zapanta
Julian Det De Villa Zapanta's answer
2 answers (Tutor Details)
The proof relies on the rationalisation radicals.

As for part 2 of the question, it requires you to view the sum in pairs and notice that it will sum up to 0 leaving behind the initial and the final radicald of the entire sum.