PLEASE HELP!! i rlly dont understand

An explanation or answer is good. It doesn’t matter which one

shtirl [24]

You have to plug in the numbers for x

7 0

3 years ago

The perimeter of a rectangle was 60 centimeters. The length is 4 centimeters longer than the width, w. What equation could be us

Black_prince [1.1K]

Answer:

a. 2w + 2(w+4) = 60

3 0

3 years ago

Read 2 more answers

When the area in square units of an expanding circle is increasing twice as fast as its radius in linear units, the radius is...

enot [183]

Answer:

c. $\frac{1}{\pi}$

Step-by-step explanation:

We have been given that the area in square units of an expanding circle is increasing twice as fast as its radius in linear units

We will use derivatives to solve our given problem.

We know that area (A) of a circle is equal to $A=\pi r^2$ .

Let us find derivative of area function with respect to time.

$\frac{dA}{dt}=\frac{d}{dt}(\pi r^2)$

Bring out constant:

$\frac{dA}{dt}=\pi \frac{d}{dt}(r^2)$

Using power rule and chain rule, we will get:

$\frac{dA}{dt}=\pi(2r)* \frac{dr}{dt}$

$\frac{dA}{dt}=2\pi r*\frac{dr}{dt}$ Here $\frac{dr}{dt}$ represents change is radius with respect to time.

We have been given that area of an expanding circle is increasing twice as fast as its radius in linear units. We can represent this information in an equation as:

$\frac{dA}{dt}=2\frac{dr}{dt}$

$2\pi r* \frac{dr}{dt}=2\frac{dr}{dt}$

$2\pi r=2$

$\frac{2\pi r}{2\pi}=\frac{2}{2\pi}$

$r=\frac{1}{\pi}$

Therefore, the radius is $\frac{1}{\pi}$ and option 'c' is the correct choice.

6 0

3 years ago

A new bridge structure requires triangles that are in a ratio of 1:1. If AC = 2x + 10 and EC = 4x − 18, find the distance betwee

gavmur [86]

Answer: The required distance between the top and bottom of the bridge is 76 feet.

Step-by-step explanation: Given that a new bridge structure requires triangles that are in a ratio of 1:1.

AC = 2x + 10 and EC = 4x − 18.

We are to find the distance between the top and bottom of the bridge, in feet.

Since the two triangles ACB and DCE are in the ratio 1 : 1, so their corresponding sides are also in the ratio 1 : 1.

The sides AC and EC are corresponding to each other, so we must have

$AC:EC=1:1\\\\\Rightarrow \dfrac{AC}{EC}=\dfrac{1}{1}\\\\\Rightarrow AC=EC\\\\\Rightarrow 2x+10=4x-18\\\\\Rightarrow 4x-2x=10+18\\\\\Rightarrow 2x=28\\\\\Rightarrow x=\dfrac{28}{2}\\\\\Rightarrow x=14.$

Therefore, the distance between the top and bottom of the bridge is

$EA\\\\=EC+AC\\\\=4x-18+2x+10\\\\=6x-8=6\times14-8\\\\=84-8\\\\=76~\textup{feet}.$

Thus, the required distance between the top and bottom of the bridge is 76 feet.

6 0

4 years ago

If P(A) = 1/6 , P(B) = 5/12, and P(A\B) + P(B\A) = 7/10 Find P(AUB)

Nesterboy [21]

Probability is the likelihood or chance that an event will occur. The probability of P(AUB) is 1/2

<h3>Conditional probability</h3>

Probability is the likelihood or chance that an event will occur. Given the following parameters

If P(A) = 1/6

P(B) = 5/12

P(A\B) + P(B\A) = 7/10

Required

p(AUB)

Recall that:

P(A|B)=P(AnB)/P(B)

P(B|A) = P(BnA)/P(A)

P(AnB)/P(B) + P(BnA)/P(A) = 7/10
12/5P(AnB) + 6P(BnA) = 7/10

42/5P(BnA) = 7/10
6/5P(BnA) = 1/10
6P(BnA) = 1/2
P(BnA) = 1/12

<u>Determine P(AUB)</u>

P(AUB) = P(A) + P(B) - P(AnB)
P(AUB) = 1/6 + 5/12 - 1/12
P(AUB) = 1/6 + 4/12
P(AUB) = 2+4/12
P(AUB) = 1/2

Hence the probability of P(AUB) is 1/2

Learn more on probability here: brainly.com/question/24756209

6 0

3 years ago