Step-by-step explanation:
(a) dP/dt = kP (1 − P/L)
L is the carrying capacity (20 billion = 20,000 million).
Since P₀ is small compared to L, we can approximate the initial rate as:
(dP/dt)₀ ≈ kP₀
Using the maximum birth rate and death rate, the initial growth rate is 40 mil/year − 20 mil/year = 20 mil/year.
20 = k (6,100)
k = 1/305
dP/dt = 1/305 P (1 − (P/20,000))
(b) P(t) = 20,000 / (1 + Ce^(-t/305))
6,100 = 20,000 / (1 + C)
C = 2.279
P(t) = 20,000 / (1 + 2.279e^(-t/305))
P(10) = 20,000 / (1 + 2.279e^(-10/305))
P(10) = 6240 million
P(10) = 6.24 billion
This is less than the actual population of 6.9 billion.
(c) P(100) = 20,000 / (1 + 2.279e^(-100/305))
P(100) = 7570 million = 7.57 billion
P(600) = 20,000 / (1 + 2.279e^(-600/305))
P(600) = 15170 million = 15.17 billion
Answer: 
Step-by-step explanation:
I hope you mean y = x² - 12 and not y = 2x - 12.
You switch the y and x variables:
x = y² - 12
And solve for y:
x + 12 = y²
Veronica traveled at 85 miles for 6 days and 52 miles on the final day making the total number of days traveled 7 days
<em><u>Solution:</u></em>
Veronica traveled 562 miles to Venice, Florida
She drove 85 miles every day
Let "d" be the number of days she drove 85 miles per day
On the last day of her trip she only drove 52 miles
Therefore, we frame a equation as,
Total miles = 85 miles every day for "d" days + last day
Total miles = 85(d) + 52
Total miles = 85d + 52
562 = 85d + 52
85d = 562 - 52
85d = 510
d = 6
She traveled at 85 miles for 6 days and 52 miles on the final day making the total number of days traveled 7
Just measure the width (or height, if you'll be stacking the pennies
a mile high) of a penny, then divide 5280 feet by whatever you find.
This is a great activity for a class, and in fact a good way to start
the project. First take one penny, and work out an answer. Then get
100 pennies, and measure them; do the same calculation to see how many
pennies it will take to make a mile. There will probably be a
difference, because you can measure 100 pennies more accurately than a
single penny. Or maybe you have a micrometer that will measure one
penny precisely. Which is better can be a good discussion starter. And
don't forget to try it in metric, too.
Just to illustrate, using a very rough estimate of a penny's width,
let's say a penny is about 3/4 inch wide. The number of pennies in a
mile will be
5280 ft 12 in 1 penny
1 mile * ------- * ----- * ------- = 5280 * 12 * 4/3 pennies
1 mi 1 ft 3/4 in
This gives about 84,480 pennies. (This method of doing calculations
with units is very helpful, and would be worth teaching.)
If we measure 100 pennies as 6 ft 1 in, we will get
5280 ft 100 pennies
1 mile * ------- * ----------- = 5280 * 100 * 12 / 73 pennies
1 mi 6 1/12 ft
This gives us 86794.5205 pennies in a mile.
Answer:
-7x -13= -48 (add 13 to both sides)
-7x = -35 (divide both sides by -7)
x= 5 (is your answer)
