Answer:
The common difference would be calculated as:
(a21-a19)/2
(-164--(-58 ))/2 (Replacing the values )
(-164 +58)/2 (Changing signs)
(-106)/2(Subtracting)
-53
Then we are going to replace the common difference(d) in the sequence formal with the 21st term . It is done for finding the first term of the sequence.
a21=a0+d*(n-1)
-164=a0+-53*(21-1) (Replacing the values)
-164=a1-53(20) (Subtracting)
-164=a1-1060 (Multiplying )
-164+1060=a1 (Adding 1060 on both sides of the equation)
896=a1
The answer would be : an= 896-53*(n-1), which is the option B.
PLEASE MARK ME AS BRAINLIEST
F(x+6) +2 up and right in a graph is positive
Th matrix is missing. The matrix is :

Solution :
The column of the matrix are
,
, 
Now each of them are vectors in
. But
has dimensions of 2. But there are 3 column vectors, hence they are linearly dependent.
Therefore, the column of the given matrix does not form the
as the set contains
than there are entries in each vector.
Therefore, option (D) is correct.
Riley's age = r
Riley's brother's age = r/4
If Riley was 11 five years ago, Riley is currently 11 + 5 years old, or 16 years old.
Now we just need to use r/4 to find Riley's brother's age:
16 /4 = 4
Riley's brother is 4 years old.
Hope this helps!