Answer:
Explanation:
23) a) n - (n+1)
Remove the parenthesis by multiplying (n+1) by (-1)
n - (n+1) = n - n - 1 = -1
b) n(n+1) = n*n + n*1
= n² + n
c) When we are adding the two numbers it is,
n² + n - 1. This will always be odd because n² + n will always be even and when we subtract 1 from that it will be odd
Example: Take n = 3
n² + n = 3*3 + 3 = 9 + 3 =12; So, n² + n -1 = 12- 1 =11 --> odd
When n = 7
n² + n = 49 + 7 = 56 ; So, n² + n -1 = 56-1 = 55 ---> odd
When n =8
n² + n = 64 + 8 = 72; So, n² + n -1 = 72 -1 = 71
When n = 16
n² + n = 256 +16 = 272 ; So, n² + n - 1 = 272 - 1 = 271 ----->odd