Respuesta :

The answer is 20 since you are going forward 20; trying to find the space in between. 
VanillaAngelic
If you count from -10 to 10 on the line, the answer is 20.


You can also use 0 as a middle point so -10 is 10 spaces away from 0 and 10 is 10 spaces away from 0 so 10 + 10 = 20.