suppose that a population has a growth rate of r per member in unit time, with r> 0.

show that the time required for the population to double its initial size (called the doubling time) is (log2)/r.

Hello there!

A model to see the growth of a certain population is the exponential model.

If the initial population is P, then the model can be written as

Where t is the time, and r is growth rate.

and f(0) = P

Then we want to know the time needed for the initial population to be doubled, this is f(x) = 2P, where x is the time that we want to find.

then

then x= ln(2)/r

50 min

step-by-step explanation:

they will be decreasing both their times in half

60 / 2 = 30

40/2 = 20

30 + 20 = 50

step-by-step explanation:

ok so im not 100% sure but you would start by adding 5.1t and 1.9t beacuse they have the same variable. that is 7t.   then add -3.6 + 1.2 which is -2.4

so then keep that as -2.4 + 7t. i apologize if this is incorrect. best luck on your test < 3