Answer: x+5<-7
Step-by-step explanation:
1) Our unknown number is x, and using the word "sum" from the question, we can figure out that we are adding--in the end, we get x+5
2) So we know the first part of the equation is x+5, but what's next? After that, it says "is less than -7". The less than sign is <, so when we put all of it together, we get x+5<-7