Step-by-step explanation:

Answer:
1.645 feet
Step-by-step explanation:
To solve this you must divide the total length by 5. 8.225/5=1.645. Each board will be 1.645 feet long
Completing the square follows the principle of taking

and converting it into

where d is the 'correctional number' as I like to call it - i.e. the number that converts the expanded bracket into the +c, since the expanded bracket will give us

.
In this case, 2/2=1 so we have the first part:

.
Expanding this gives us

. We need c to be 9, so we can just add 8.
Putting this together:

Now we can solve it more easily.
Rearranging:
Solution: We know that e is numerical constant and is equal to 2.71828.
Therefore log( 6 x 2.71828) = 1.21