Answer:

Step-by-step explanation:
The formula of a volume of a square pyramid:

a - base edge
h - height of a pyramid
We have H = 8in.
Substitute and solve for a:

Answer:
Eric's expression is :

and Andrea's is :

In Eric's expression, 20 represents the initial amount of substance with which he has started the experiment.
is the amount of substance left after each time period (in this case, each week).The variable w in this case represents the number of weeks.
Andrea's expression can be written as :

The one outside of parentheses represents the initial amount of the substance. The one inside of parentheses represents 100% of the original amount of the substance. 0.5 represents the 50% of the substance that is lost each time period. The variable w in this case represents the number of weeks.
X^2 + 16x + ?
a^2 + 2ab + b
(a + b)^2 which is a perfect square.
To find b to determine the last value, you divide 16x by 2x.
so:
b = 8
the last value would be 8^2 which is 64.
Hence answer is C - 64
<h2><u>D:</u></h2><h2><em /></h2><h2><em>The awnser is </em><u><em>4</em></u><em>!! Hope this helps!! <3</em></h2>