Direct proof question, "The product of an even integer and an odd integer is even".
I didnt understand
Let say X = 2a +1 while y = 2b+1
Why you need to multiply xy rather x+y, as you can see below:
XY = (2a+1)(2y+1) <- correct
X+Y = 2a+1+2y+1 <- Incorrect
Can you elobrate why it multiply rather than add. Kinda lost. Thank you maám/sir.