s + 9
(x + 9)
The expression is 9*x.
20 - 11 = 9
If you want to say "Nine is less than a number k," you would write 9<K. If you're asking for an equation, e.g. "Nine less than a number k is equal to that number divided by three," you would write k - 9.
9x + 11
N/9
X+9
9+5 = 14
7 more than the product of 6 and 9
2n/6 - 9 or n/3 - 9
(14x2)-9