Question

( k>3 )
( =(4-2)(n-1+2)(2(n-1)+1) )
( frac{(n-1)(n) times 3}{2 times 3} )
( frac{2}{frac{n-1}{6}} frac{(2 n-1)}{6}+frac{3 n(n-1)}{6} )
( =frac{n(n-1)}{6}[24-1+3] )
( =frac{n(n-1)}{6}(2 n+n)=frac{n(n-1)(n+1)}{3} )
Teacher Signat

# n-1 . Prove that t(t+1) = n(n-1) (n+1) for all natural for all natural numbers n > 2. 1 = 1

Solution