Math Help - proof

prove 4 + 12 +20 + ... +(8n-4) =4n^2

true for n=1

(8n-4) + 8(n+1)-4 = 4n^2 +8(n+1)-4

simplify but then how do i finish off?

Hello

Originally Posted by skystar

(8n-4) + 8(n+1)-4 = 4n^2 +8(n+1)-4

simplify but then how do i finish off?

Once you've simplified the expression, try to factor it by 4.

so will this give a n+2 term and shows its true for all of the sequence.

Originally Posted by skystar

so will this give a n+2 term and shows its true for all of the sequence.

If you meant n+1, that's it !