Question

Prove that x^2- x is divisible by 2 fore all the positive integer x​

Answer 1

Step-by-step explanation:

this is probably not the book proof but it's a logical proof

x^2-x = x(x-1)

now if x is odd

in x(x-1), x-1 would be even or 0 and therefore divisible by 2

if x is even then in x(x+1) we get x as even which implies it is divisible by two