The value of O is 6 on the number line. We can find this by adding together the ratio 2:1 to get 3, and then dividing 12 by 3 to find the value of one part of the ratio, which is 4. We can then multiply 2 by 4 to get 8, which would be the value of the line NO. Now because N is -2 on the number line, we simply need to add 8 to -2 to get 6. I hope this helps!