Algebraic proof GCSE maths - multiple of 3 question

@3minutemaths for quick reminder and walkthrough GCSE maths videos.


This video is all about algebraic proof and forms part of the playlist on algebra proof.

The question is aimed at grade 7+ GCSE maths and it's probably harder to understand - than it is to calculate. Also the centre -ve can cause a bit of a problem:

Prove that (3n + 1)^2 - (3n - 1)^2 is always a multiple of 3, for all positive integer values of n.

This might be written as (3n + 1)squared - (3n - 1)squared.


I hope the video helps and please do leave a comment - thanks!


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[kingjarif]

Hi sir why u dont do facecam now..We want facecam.

[Maddy_Stevens]

hi can you do some more examples of this video as i still dont fully understand