For all of these, let n = the unknown number.
25) "Five less than a number" becomes 5 - n
"At least" tells you your number is greater than or equal to - 2.
Put it all together.
5 - n ≥ - 2
- n ≥ - 2 - 5
- n ≥ - 7
Divide by - 1 to isolate the variable. This flips the operation.
n ≤ 7
26) "The difference between a number and 6" tells you to do n - 6
"no more than" means this is a less than or equal to sign.
n - 6 ≤ 5
n ≤ 5 + 6
n ≤ 11
27) "The sum of a number and 7" becomes n + 7
"more than" is a greater than sign
n + 7 > 1
n > 1 - 7
n > - 6
28) "The difference between a number and 10" becomes n - 10
Obvious one, "greater than" is... just that.
n - 10 > 9
n > 9 + 10
n > 19
29) "Four less than a number" is 4 - n
Another obvious one in "less than"
4 - n < 11
- n < 11 - 4
- n < 7
Divide by - 1 on both sides to isolate the variable
n > - 7