1.nXn/n+1=n-n/n+1.2.
nxn/(n+1)=n-n/(n+1)
n*n/(n+1)=n-n/(n+1)(n^2)/(n+1)=n*(n+1)/(n+1)-n/(n+1)(n^2)/(n+1)=(n^2+n-n)/(n+1)=(n^2)/(n+1)
