Ask question

Ask question

All categories

4 years ago

10

P. John roller skates with a constant

1 answer:

Vitek1552 [10]4 years ago

3 0

Answer:

2 1/2 hours

Step-by-step explanation:

1. multiply 12 by 2 to get 24

2. divide 12 by 2 to get 6 mph (miles per hour)

3. Add the 6 and 24

You might be interested in

jo has a total of 61 dimes and quarters in her piggy bank. she has 3 more quarters than dimes. the coins have a total value of $

Zepler [3.9K]

D+Q=61 => D=61-Q
3+D=Q

10D+25Q=1090

10(61-Q) + 25Q=1090
610-10Q+25Q=1090

610+15Q=1090
-610 -610

15Q=480

480/15=32

32 quarters

4 0

3 years ago

Read 2 more answers

Which type of study best describes the following research most likely to be done? A teacher wants to know how fast all her stude

Yakvenalex [24]

Census

_____________________________________

<em>*100% CORRECT ANSWERS</em>

Question 1

Which type of study best describes the following research most likely to be done?

A researcher is testing out a brand new type of safety suit for fires and is trying to test the maximum threshold of the suit.

Simulation Study

Question 2

Which type of study best describes the following research most likely to be done?

A test is being conducted on a new medicine that is supposed to heal cuts faster. One group is given the actual medicine in a gel type of ointment to apply to the cuts. The second group is given just regular Vaseline that looks like the medicine but has not benefit to put on the cut. The results are then compared.

Experimental Study

Question 3

Which type of study best describes the following research most likely to be done?

A researcher is wanting to research the after effects of plant growth after a nuclear reactor meltdown and decides to study plants within a 50 mile radius of the power plant that had a catastrophic melt down in 2011.

Observational Study

Question 4

Which type of study best describes the following research most likely to be done?

A study is being conducted by an insurance actuary and he wants to determine how often American teen drivers that are on the honor roll get into wrecks.

Sampling

Question 5

Which type of study best describes the following research most likely to be done?

A teacher wants to know how fast all her students for a particular period can complete a multiplication quiz to check their mental math abilities. So, all of her students are tested on a computer and the time of each and every student is recorded.

Census

6 0

3 years ago

Evaluate Dx / ^ 9-8x - x2^

Solnce55 [7]

It depends on what you mean by the delimiting carats "^"...

Since you use parentheses appropriately in the answer choices, I'm going to go out on a limb here and assume something like "^x^" stands for $\sqrt x$ .

In that case, you want to find the antiderivative,

$\displaystyle\int\frac{\mathrm dx}{\sqrt{9-8x-x^2}}$

Complete the square in the denominator:

$9-8x-x^2=25-(16+8x+x^2)=5^2-(x+4)^2$

Now substitute $x+4=5\sin y$ , so that $\mathrm dx=5\cos y\,\mathrm dy$ . Then

$\displaystyle\int\frac{\mathrm dx}{\sqrt{9-8x-x^2}}=\int\frac{5\cos y}{\sqrt{5^2-(5\sin y)^2}}\,\mathrm dy$

which simplifies to

$\displaystyle\int\frac{5\cos 
y}{5\sqrt{1-\sin^2y}}\,\mathrm dy=\int\frac{\cos y}{\sqrt{\cos^2y}}\,\mathrm dy$

Now, recall that $\sqrt{x^2}=|x|$ . But we want the substitution we made to be reversible, so that

$x+4=5\sin y\iff y=\sin^{-1}\left(\dfrac{x+4}5\right)$

which implies that $-\dfrac\pi2\le y\le\dfrac\pi2$ . (This is the range of the inverse sine function.)

Under these conditions, we have $\cos y\ge0$ , which lets us reduce $\sqrt{\cos^2y}=|\cos y|=\cos y$ . Finally,

$\displaystyle\int\frac{\cos y}{\cos y}\,\mathrm dy=\int\mathrm dy=y+C$

and back-substituting to get this in terms of $x$ yields

$\displaystyle\int\frac{\mathrm dx}{\sqrt{9-8x-x^2}}=\sin^{-1}\left(\frac{x+4}5\right)+C$

4 0

3 years ago

HELP ASAP I WILL GIVE 20 POINTS HELPPPPPPPPPPPP

Nikolay [14]

52s + 30b because 52 x s + 30 x b = 52s + 30b

6 0

3 years ago

Read 2 more answers

Please help it’s urgent don’t give me the wrong answer :(

olasank [31]

Answer:

i dont know

Step-by-step explanation:

this is a new answer bc someone deleted my very helpful one

6 0

3 years ago