Answer:

Step-by-step explanation:
We have been given that the elevation of driskill mountain Louisiana is 163 meters above sea level. The death Valley has an elevation of -86 meters.
We can represent this information in an inequality as:
. Our inequality means that the elevation of death valley is less than elevation of driskill mountain.
Find the mean of the first four test scores first.
(Add all numbers in set and divide by how many numbers there are)
81 + 87 + 71 + 89 = 328 / 4 = 82
Then, find the mean with the 85 added as the fifth term.
81 + 87 + 71 + 89 + 85 = 413 / 5 = 82.6
The impact that the 85 had on the mean test score was that the mean/average increased by 0.6.
This does not look easy to factor, so I'd suggest using the quadratic formula:
-1 plus or minus sqrt( 1-4(3)(-5) )
x = -----------------------------------------------
2*3
-1 plus or minus sqrt(61)
= ------------------------------------
6
Thus, there are 2 real, unequal, irrational roots / solutions.