At the moment a certain medicine. Is injected, it's concentration in the blood stream is 120 mg/L. From that moment forward, the medicine concentration drop by 30% each hour. Write a function that gives the medicines concentration in milligrams Per liter, C(t),t hours after the medicine was injected

Step-by-step explanation:

From that moment forward, the medicine concentration drop by 30% each hour. It means that the rate at which the medicine concentration is dropping is exponential. We would apply the formula for exponential decay which is expressed as

A = P(1 - r)^t

Where

P represents the initial concentration.

A represents the final concentration after t hours.

t represents the number of hours.

r represents the rate

From the information given

P = 120 mg/L

r = 30% = 30/100 = 0.3

The expression becomes

C(t) = 120(1 - 0.3)^t

C(t) = 120(0.7)^t

it's d.

step-by-step explanation:

because: -1(4x + 1y) +2 (1x-3y) distribute each number into the parenthesis.

then you would get: -4x - 1y + 2x -6y combine like terms

and get: 2x -7y

hope my answer has you if not then i'm sorry.