Answer:
x + 11
Step-by-step explanation:
Expressions don't have equal signs in them like equations do, so all we are asked to do is to write in numbers and variables what the words translate to mathematically. There is nothing to solve because of the lack of the equals sign. The word "sum" means the answer you get to something when you add, so we know we are adding. We are adding an unknown x to 11, so the expression mathematically looks like this:
x + 11
