4 < = x + 4 < = 8.....subtract 4 from all sections
4 - 4 < = x + 4 - 4 < = 8 - 4...simplify
0 < = x < = 4
this would produce a number line with a solid circle on 0 and a solid circle on 4, with shading in between....just like the graph shown in the picture u posted.
so the expression u would add would be : x + 4
k, n - integers
2k+1 - an odd integer
2n+1 - another odd integer
The product of them:
(2k + 1)(2n + 1) =
= 4kn + 2k + 2n + 1 =
= 2(2kn + k + n) + 1
The product of integers (2kn) is integer
and the sum of them (2kn+k+n) also is integer
So (2k + 1)(2n + 1) = 2(2kn + k + n) + 1 is an odd integer
12 ) 18
13) 54
14) 28/54 (8weeks x 7 days) = 1/2
18/24 = 3/4
therefore rates not equal
15) 0 and 0 ;1 and 4; 2 and 8;3 and 12