A matrix is diagonal if

In other words, you want non-zero elements only when the indices of the row and the column are the same: the first element of the first row must be non zero, the second element of the second row must be non-zero, and so on. All other elements must be zero.
9y-8y-y= 9-8-1 = 0y =0
subtract all like terms
Answer:

Step-by-step explanation:
Geometric sequence
Each term in a geometric sequence can be computed as the previous term by a constant number called the common ratio. The formula to get the term n is

where
is the first term of the sequence
The problem describes Georgie took 275 mg of the medicine for her cold in the first hour and that in each subsequent hour, the amount of medicine in her body is 91% (0.91) of the amount from the previous hour. It can be written as
amount in hour n = amount in hour n-1 * 0.91
a)
This information provides the necessary data to write the general term as

b)
In the 8th hour (n=8), the remaining medicine present is Georgie's body is



Step-by-step explanation:
There are 12 games in the population. You need to use a random number generator to choose 2 of these games.
RandomSample[{1,2,3,4,5,6,7,8,9,10,11,12},2]
Let's say the first sample you get is {1,5}. That corresponds to game times of 8 minutes and 7 minutes. The mean game time for that sample is 7.5 minutes. So the first row in your table would be:
![\left[\begin{array}{ccc}Sample&List\ of\ Game\ Times&Mean\ Game\ Time\\1&8,7&7.5\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7DSample%26List%5C%20of%5C%20Game%5C%20Times%26Mean%5C%20Game%5C%20Time%5C%5C1%268%2C7%267.5%5Cend%7Barray%7D%5Cright%5D)