At the moment a certain medicine is injected, its concentration in the bloodstream is 120 milligrams per liter.
from that moment forward, the medicine's concentration drops by 30% each hour.
write a function that gives the medicine's concentration in milligrams per liter, cl(t), t hours after the
medicine was injected.

step-by-step explanation:

what is the figure? attach a picture.

the solution of the equation is 2.23 ⇒ answer b

step-by-step explanation:

* lets revise the meaning of exponential function

- the form of the exponential function is y = ab^x, where a ≠ 0, b > 0 ,  

  b ≠ 1, and x is any real number

- it has a constant base b

- it has a variable exponent x

- to solve an exponential equation, take the log or ln of both sides,  

  and solve for the variable

* lets solve the problem

∵

- the base is 7 and the exponent is x

- insert ㏑ in both sides

∴

- use the rule

∴ x ㏑(7) = ㏑(77)

- to find x divide both sides by ㏑(7)

∴

* the solution of the equation is 2.23 to the nearest 2 decimal places

the answer to question 1 is -8, 28.

step-by-step explanation: