M is an odd integer. For each of the following numbers, check if the number is odd.

Question

2m- 1
2m +1
m^2 - m
m^2 +m+1

Answer 1

2 m is even ... multiplication by an even quantity
... so the 1st two numbers are odd

odd squared is odd
... odd minus (or plus) odd is even
... 3rd number is even

odd plus odd is even
... even plus odd is odd
... 4th number is odd

Answer 2

Everyone will be odd but m^2 - m.