All categories

3 years ago

What's the equation p/7=3/21

Mathematics

1 answer:

ella [17]3 years ago

6 0

p/7=3/21
21p = 7·3
21p = 21
p = 21/21
p = 1

You might be interested in

The rate of change of the number of mountain lions N(t) in a population is directly proportional to 725 - N(t), where t is the t

wolverine [178]

Answer:

a) The implied differential equation is $\frac{dN}{725 - N} = kdt$

b) The general equation is $N = 725 - C e^{-kt}$

c) The particular equation is $N = 725 - 325 e^{-0.49t}$

d) The population when t = 5, N(5) = 697 = 700( to the nearest 50)

Step-by-step explanation:

The rate of change of N(t) can be written as dN/dt

According to the question, $\frac{dN}{dt} \alpha (725 - N(t))$

$\frac{dN}{dt} = k (725 - N)\\\frac{dN}{725 - N} = kdt$

Integrating both sides of the equation

$\int {\frac{1 }{725 - N}} \, dN = \int {k} \, dt\\- ln (725 - N) = kt + C\\ ln (725 - N) = -(kt + C)\\725 - N = e^{-(kt + C)} \\725 - N = e^{-kt} * e^{-C} \\725 - N = C e^{-kt}\\N = 725 - C e^{-kt}$

When t = 0, N = 400

$400 = 725 - C e^{-k*0}\\400 = 725 - C\\C = 725 - 400\\C = 325$

When t = 3, N = 650

$650 = 725 - (325 * e^{-3k})\\325 * e^{-3k} = 75\\e^{-3k} = 75/325\\e^{-3k} = 0.23\\-3k = ln 0.23\\-3k = -1.47\\k = 1.47/3\\k = 0.49$

The equation for the population becomes:

$N = 725 - 325 e^{-0.49t}$

At t = 5, the population becomes:

$N = 725 - 325 e^{-0.49*5}\\N = 725 - 325 e^{-2.45}\\N = 696.95\\N(5) = 697$

N(5) = 700 ( to the nearest 50)

6 0

3 years ago

José paid $47.00 for 4 movie tickets. Each ticket cost the same amount. What was the cost of each movie ticket in dollars

Nataly [62]

Answer:

$11.75

Step-by-step explanation:

To find the cost of each,

you have to divide the amount paid by the amount bought

47.00 (amount paid) / 4 (amount bought) = 11.75 (total cost of each)

6 0

3 years ago

32x + 23 - 42 = 365 What does x equal?

liubo4ka [24]

As you bring all the non-variable numbers over to the right side, it becomes 384 which you then will divide the 32 in x which gives us 12. so x=12

6 0

4 years ago

What is the perimeter of the triangle? (geometry)

Degger [83]

The perimeter is the sum of all its sides.
That is for all triangles or polygons in general.

Good luck!
M.

3 0

3 years ago

Look at the pic in the corner it’s math

Schach [20]

Answer:

The third one

Step-by-step explanation:

Its because we need to find the number that it has grown.

so we add the number that it grew to the size it was before.

6 0

3 years ago

Read 2 more answers