Respuesta :

Answer:

D is true, E is true, F is true

Step-by-step explanation:

Hello,

n is an odd number it means that n = 2a+1 where a is integer

A

[tex]n^2-1=(2a+1)^2-1=4a^2+4a+1-1=4a(a+1)[/tex]

this is not an odd number

B

[tex]n(n-1)=(2a+1)2a[/tex]

this is not an odd number

C

[tex](n-1)^2=(2a+1-1)^2=4a^2[/tex]

this is not an odd number

D

[tex]n^2+2=(2a+1)^2+2=4a^2+4a+1+2=4a^2+4a+3= 2(2a^2+2a+1)+1[/tex]

so this is an odd number

E

[tex]n(n-2)=(2a+1)(2a-1)=4a^2-1=4a^2-2+1=2(2a^2-1)+1[/tex]

so this is an odd number

F

[tex](n-2)^2=(2a+1-2)^2=(2a-1)^2=4a^2-4a+1 = 2(2a^2-2a)+1[/tex]

this is an odd number

hope this helps