8 marksThe Real Number System – ℝ
CAPE Pure Mathematics Unit 1 · May/June 2015 · Paper 2 · Question 1(c)
Given that S(n) = 5 + 5² + 5³ + 5⁴ + ... + 5ⁿ.
Use mathematical induction to prove that 4S(n) = 5ⁿ⁺¹ – 5 for n ∈ N.
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