Question

Why is the sum of two odd numbers even?

Answer 1

Answer:

a) and b) in photo.

there is no point left outside the circles, then 11+15 is even.

c) yes it is, because if both numbers are odd, they will have one point outside the circles each, and those two points will form an other pair.

odd number: 2n+1

even number: 2m

(m and n represent any natural number)

2n+1 + 2k+1= the sum of two odd numbers

=2(n+k) +2

=2(n+k) +2 =2(n+k+1)

the sum of 3 natural numbers will be a natural number too. let be m=n+k+1 with m n and k natural numbers.

=2m even number