Prove n^3-n is multiple of 6 for all n
factoring gives form n(n+1)(n-1) from here it should be realised that if n is not a multiple of 3 then n-1 is or n+1 is as multiples of 3 go up in 3s. Hence one of the values either n,n-1 or n+1 must be multiple of 3.
AN
Related Maths GCSE answers
All answers ▸Simplify the expression: (2a + a)x(5a - a)
f(x) = x^2 + 2x - 3. Where does the graph of the function f intersect the x-axis?
A rectangle has an area of 20 cm^2. Its length and width are enlarged by scale factor 3. Find the area of the enlarged rectangle.
If the probability of picking a red ball out of bag A is 2/5 and the probability of picking a red ball out of bag B is 3/7, what is the chance that you will pick exactly 2 red balls if you pick 2 balls from A and 1 ball from B? The balls are not replaced.