<u>Answer:</u>
The correct answer option is B. 2 = 3x + 10x^2
<u>Step-by-step explanation:</u>
We are to determine whether which of the given equations in the answer options can be solved using the following expression:

Here,
and
.
These requirements are fulfilled by the equation 4 which is:

Rearranging it to get:

Substituting these values of
in the quadratic formula:


The only one with two obtuse and two right angles.
Trapezoid
It would take her about 15 seconds
To find the answer, use
, and then use the equation
To find it's half life.