Answer:
$1445.11
Step-by-step explanation:
The formula to use would be:

Where
F is the future amount (what we want to find)
P is the present (principal) amount (this is 400)
r is the rate of interest, monthly (1.8% or 0.018)
t is the time in months (6 years = 6 * 12 = 72)
Now substituting, we get:

After 6 years, the CD will be worth $1445.11
There are many equations that has a constant of
proportionality, might want to make it more specific.
The correct product should have been:
<span>(–4x + 9)2 = </span>(-4x)2 + 2(-4x)(9) + 9^2 = 16x6 - 72x +81
The result is a trinomial and not a binomial nor a difference of two squares.
So, the answer is:
C = Kylie did not understand that this is a perfect square trinomial, and she did not determine the product correctly.