For this case we have the following expression:

From here, we must clear the value of a.
We then have the following steps:
Place the terms that depend on a on the same side of the equation:

Do common factor "a":

Clear the value of "a" by dividing the factor within the parenthesis:

Answer:
The clear expression for "a" is given by:

The answer to this question is 2
Answer:
A clinical test on humans of a new drug is normally done in three phases. Phase I is conducted with a relatively small number of healthy volunteers. For example, a phase I test of a specific drug involved only 7 subjects.
Step-by-step explanation:
Answer: A diameter goes straight across the circle and passes through the center point (point M). A radius stops at the center point, making the line go halfway across the circle (basically half the diameter). A chord goes across the circle, but does not go through the center point. Therefore, the answer is C, because it does not go through the center point.