Divisibility proofs with identities
Divisibility proofs with identities
Secondary 2
4 marks
TGM Original Questions
If \(x\) is a positive integer, show that \((6x+1)^2-4(6x+1)-3\) is always divisible by 6.[4]
Solution:
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Answer:\(6(6x^2-2x-1)\). For integer \(x\), the bracket is an integer. Hence the expression is divisible by \(6\).
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