Answer:
First get the formula for your pattern in the form of TN. Where d represents your difference and a represents your first term. Then equate the -401 to your formula and solve for n
The value of f(-6) is -12.2
Explanation:
Given that the function 
We need to determine the value of f(-6)
The value of f(-6) can be determined by substituting the value for
in the function and simplify the function.
Hence, let us substitute
in the function, we get,

Let us apply the rule
, we get,

Multiplying the numbers, we get,

The value of 
Substituting the value of
, we get,

Subtracting the denominator, we have,

Dividing, we have,

Rounding off to the nearest tenth, we have,

Thus, the value of f(-6) is -12.2
Hi There!
Step-by-step explanation and Answer:
21 * 0.2 = $4.2 (Discount)
21 - 4.2 = $16.8 (Sale Price)
Hope This Helps :)
If patio is square it means that area of if is

where a is one side
Now we can substitute A=200 and solve eq

a=

a=14.1421
Now we are rounding to the nearest tenths
a=14.1 because next number is 4 and is less then 5.
The result is 14.1