Answer:
Step-by-step explanation:
product of two consecutive numbers is always even.
n(n+1)
case 1
if n is odd,let n=2k+1,where k is an integer
n+1=2k+1+1=2k+2=2(k+1)
n(n+1)=(2k+1)[2(k+1)]=2(2k+1)(k+1)=even number.
case 2
if n is even,let n=2m,where m is an integer.
n+1=2m+1
n(n+1)=2m(2m+1)=even integer.
so in both cases n(n+1) is even.