C.) 5 is the value of X and the value of Y is 5/2
we have been asked to perform 
The given expression can be written as

Now it can be re-written as below

Answer:
14
Step-by-step explanation:
median is the number in the very middle when the numbers are organized in order:
1, 2, 7, 13, 14, 17, 18, 18, 20
if we start taking away from both ends we’ll get the answer
2, 7, 13, 14, 17, 18, 18
7, 13, 14, 17, 18
13, 14, 17
14
Answer:
By examining the line plot, we find the number with the maximum number of crosses or occurrences. This gives the mode of the data set. We find the smallest and the largest number from the data set and find their difference and this difference is the range of the given data set.
The only number all of these numbers can be divided by is 2. Therefore, the GCF is 2