n n\,n is an integer. Prove algebraically that the sum of (n+4)(n+3)(n + 4)(n + 3)(n+4)(n+3) and n+4n + 4n+4 is always a square number.
56 exam-style questions on Edexcel GCSE Maths Proof. Each one has a worked solution and a mark scheme showing where the marks go.