Answer:
<h2>400</h2>
Step-by-step explanation:

Given:
The quadratic equation is

To find:
The vertex of the given quadratic equation.
Solution:
If a quadratic function is
, then

We have,

It can be written as

...(i)
Here,
.



Putting
in (i), we get
On further simplification, we get
So, the vertex of the given quadratic equation is
.
Therefore, the correct option is A.
Answer:
A
Step-by-step explanation:
The formula for this type of interest is
, where A is the total amount, P is the initial investment, x is the interest rate, n is the amount of times that the investment is compounded a year, and t is the amount of years. Plugging in the numbers given, you get:


Now, she invests this into a new account, and you can set up the following equation:

, or option A.
Hope this helps!
The square will have area
.. (9 cm)^2 = 81 cm^2.
The two triangles together will have area
.. (9 cm)*(12 cm) = 108 cm^2.
The sum of the areas of those three shapes is
.. 81 cm^2 +108 cm^2 = 189 cm^2