10 ≥ 9 + v
Remember, we want to work out what v is, which means we need to get it alone one one side of the inequality.
Therefore, we need to minus 9 from both sides so that the v is isolated:
10 - 9 ≥ 9 + v - 9
The 10 - 9 becomes 1, and the 9 + v - 9 just becomes v as 9 - 9 cancels out to nothing:
1 ≥ v
Therefore, the answer is 1 ≥ v, or rather, v ≤ 1. (v is less than or equal to 1.)