Aparticular bacteria population on an athlete's foot doubles every 3 days. determine an expression for the number of bacteria n after t days, given the initial amount is 40 bacteria.

Step-by-step explanation:

The exponential growth formula is:

NOTE: This problem is asking to use N instead of A and T instead of t

Step 1: find the rate  

Step 2: input the rate to find N

Step-by-step explanation:

The growth of bacteria is an exponential function. The equation has the general form

Using the variables N and T, we can rewrite the equation as

We have two conditions:

(1) There are 40 bacteria at T = 0

(2) There are 80 bacteria at T = 3.

Insert these values into the equation.

step-by-step explanation:

the answer is 89 d

i took the test

this is a direct variation proportion. y = kx

y is the total amount due, k is the constant of variation, and x is the number of texts sent.

plug in the 3.20 and the 16 to solve for the "k". this is the constant of proportionality. it is the value that will not change.

3.20 = k(16). solving you get $.20 per text.

the equation would then be y = .20x