Dan believes that for all positive integers n3+n+6n^3 + n + 6n3+n+6 is a multiple of 4.
Which value of n n\,n shown below is a counter example to Dan’s belief?
n=6n=7n=8n=9 n = 6 \quad n = 7 \quad n = 8 \quad n = 9 n=6n=7n=8n=9n=6n=6n=6
n=7n=7n=7
n=8n=8n=8
n=9n=9n=9
257 exam-style questions on Edexcel A Level Maths Algebraic Methods, covering 7.1 Algebraic Fractions, 7.2 Dividing Polynomials, 7.3 The Factor Theorem, 7.4 Mathematical Proof, and 7.5 Methods of Proof. Each one has a worked solution and a mark scheme showing where the marks go.