x=-3 y=0 probably wrong but it’s the root of at least one of these
Answer:

Step-by-step explanation:
If t is the number of days since Sofia took the medication of 10 mg, then the amount of medication in her system after t days will be
.
So, the concentration of medicine in blood decreases by a factor of one half every day.
If we count the number of days from today and Lexi takes 10 mg of the same medicine four days later then the amount of medicine left on her body after t days will be
. (Answer)
Answer:
a / (a - 4) = a(a + 4) / ((a - 4)(a + 4)) = (a^2 + 4a) / (a^2 - 16) = -(a^2 + 4a) / (16 - a^2)
The answer is 90..........................................................................................
For this case we have that by definition, a direct variation is given in the form:

Where:
k: It is the constant of proportionality
According to the statement we have to:

Substituting:


On the other hand we have:


Answer:
