Answer: 5
Explanation:
Usually you would just do 7+-2 which is also 7-2 which equals 5 but since it's a number line you do this
You would locate 7 on the number line and do the same for -2
Once done, you would take the distance 2 is from 0 and push 7 there(basically moving it to 5) and that would be how you would use a number line to find the sum of 7 + -2
Now if the 2 was positive, this would be different and you would add the distance making it 9 but since it's negative you push it towards 0 which makes it 5
I hope this helps!