The sum of a number and 5 is less than - 7

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