Hi this question was in Advanced Higher Maths in the UK

Show that (n+1 , 3) - (n ,3 )=(n ,2)

They are written in column vector form ie n+1 at top and 3 at the bottom for example for the first. I think you have to use the n c r formula to prove the rhs

Please Help. A member kindly said it was this rule but I don't know how to prove

it for this question using the identity:

(n , r-1)+(n ,r)=(n+1, r) written as column vectors

Thanks