let 'x' represent the number and let 'y' represent whatever it is summed with

The sum of a number is 7 less than -9:

x+y=-9-7

...now, there must certainly be an error in the problem statement because these types of problems should read something like "The sum of a number and 7 is less than -9", in which case the answer would be:

x+7<-9

which simplifies to

x<-16