Prove that (3n+2)2−(3n−2)2(3n + 2)^2 - (3n - 2)^2(3n+2)2−(3n−2)2 is always a multiple of 8, for all positive integer values of nnn.
56 exam-style questions on Edexcel GCSE Maths Proof. Each one has a worked solution and a mark scheme showing where the marks go.