2+(-3) = -1
2- 3 = -1
-1=-1
The question is why though ?
It is because you keep the negative exponent which is with the biggest number. So this is how its look like +2 -3, so 3 is bigger then 2 so for that reason you keep the negative sign.
I hope that's help:)
What is the table and the box? I dont think it’s possible to answer without seeing the table.
Answer:
Here is the complete question attached with.
The mean score would decrease more than the median score.
Step-by-step explanation:
The numbers for which we have to find the mean and median are:

Here the mean, 
Median,
as median is the middle term if the observations are arranged in ascending order.
Now as the question says that we have to add a zero to see its effect.
So adding a zero we have
Mean 
Median
,as number of observations is even terms so we will add two middle numbers and divide it with
.
So we can conclude that the mean is having more variation than the median.
Mean shows as variation of
where as Median shows a variation of
only.
So our final answer is option D that is "The mean score would decrease more than the median score."
Plan A = 9 +0.17x
Plan B = 21 +0.12x
9+0.17x = 21+0.12x
X=240
9+0.17(240)=49.8
21+0.12 (240)=49.8
240 minutes and cost $49.80 each