Question

odd number x odd number = odd number?

Answer 1

yes

Answer 2

11*11 = 121

Answer 3

is there a way to prove it algebraically?

Answer 4

(2m+1)(2n+1)=4mn+2m+2n+1=2(2mn+m+n)+1=2k+1

Answer 5

Odd number = 2k +1
(2k + 1)^2 = 4k^2 + 4k + 1 = 2(2k^2+2k) + 1
2k^2 + 2k can be any number, it doesnt matter. Since any number multiplied by two is even, 2k^2 + 2k is even.

So add one to that, and you get odd.

Answer 6

yes! :)

Answer 7

2*(2k^2 + 2k) is even* is what i meant.

Answer 8

i see..thanks guys :D

Answer 9

just a few months ago they made me think these things could not be proved lol

Answer 10

try proving 0 is different from 1 :d

Answer 11

how?

Answer 12

A is the number that Ax = A
B is the number that B + x = x
are A and B the same number?

go nuts. dont hurt yourself.

remember that i said "try" :)