An arithmetic sequence takes the form

where

is the common difference between terms. You can solve for

in terms of any of the previous terms of the sequence:

for some integer

Continuing in this way, you know that the sequence can be defined explicitly in terms of the first term


Given that the 4th term is

and the 11th term is

, you have the following system of equations.

Solving this system for the two unknowns yields

and

.
So, the sequence is given explicitly by
Answer:
Area = 16.8 * 7 / 2 = 58.8 ft2
Step-by-step explanation:
Have
18.2^2 = 7^2 + a^2
-> a^2 = 18.2^2 - 7^2
-> a^2 = 282.24
-> a = 16.8
Area = 16.8 * 7 / 2 = 58.8 ft2
Answer:

Step-by-step explanation:
(2 decimal places)
If you want to arrange the tiles into a square, you will need 3.46 in each row/column.
This is physically impossible, hence you round it down to 3.
(If you round it up, you won't have enough tiles since
)
Thus, the square area will be 
Tiles left: 
The fourth option is the correct answer.
Hope this helps! ;)