n n\,n is an integer.
Prove algebraically that the sum of n(n+1)n(n + 1)n(n+1) and n+1n + 1n+1 is always a square number.
Practise CIE IGCSE Maths Proof with exam-style questions for Core and Extended tier. 14 questions, matched to the CIE IGCSE Maths (0580) specification and written in Paper 1 and Paper 3 (Core) or Paper 2 and Paper 4 (Extended) style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.