Question

give me the answer as fast as possible ​

Answer 1

Answer:

Step-by-step explanation:

14. n positive integer , then n is either 2k eller 2k + 1 for k positive integer.

if n = 2k then

n^2 - n = n(n - 1) = 2k(2k - 1) which is obviously divisible by 2.

if n = 2k + 1 then

n^2 - n = n(n - 1) = 2k(2k + 1) which is obviously divisible by 2.

thus n^2 - n is Always divisible by 2.