Need help plz help help help

PLEASE HELP ASAP!!!! PLEASEEE!!! I NEED HELP! I WILL MARK YOU THE BRAINLIEST PLEASE!!!

AVprozaik [17]

Answer: -1.8m3n2

Step-by-step explanation:

6 0

3 years ago

When Cullen cleaned behind his dresser, he found 73 cents, all in nickels and pennies. There were 25 coins. How many were nickel

Georgia [21]

Let n = number of nickels, and p = number of pennies.
The number of coins is 25, so we get this equation.
n + p = 25

The value of the coins is 0.05 per nickel, and 0.01 per penny.
0.05n + 0.01p = 0.73

Now you have a system of equations.

n + p = 25
0.05n + 0.01p = 0.73

Solve the first equation for n:
n = 25 - p

Now substitute into the second equation.

0.05(25 - p) + 0.01p = 0.73

1.25 - 0.05p + 0.01p = 0.73

-0.04p = -0.52

p = 13

There were 13 pennies.
Now we substitute 13 for p in n + p = 25 to find out the number of nickels.

n + 13 = 25
n = 12

There are 13 pennies and 12 nickels.

Check: 13 pennies and 12 nickels does total 25 coins.
13 * 0.01 + 12 * 0.05 = 0.13 + 0.60 = 0.73
The value is $0.73.
Our answer is correct.

5 0

3 years ago

20. Based on student records, 25% of the students at a large high school have a

Elenna [48]

Answer:

(E) 0.71

Step-by-step explanation:

Let's call A the event that a student has GPA of 3.5 or better, A' the event that a student has GPA lower than 3.5, B the event that a student is enrolled in at least one AP class and B' the event that a student is not taking any AP class.

So, the probability that the student has a GPA lower than 3.5 and is not taking any AP classes is calculated as:

P(A'∩B') = 1 - P(A∪B)

it means that the students that have a GPA lower than 3.5 and are not taking any AP classes are the complement of the students that have a GPA of 3.5 of better or are enrolled in at least one AP class.

Therefore, P(A∪B) is equal to:

P(A∪B) = P(A) + P(B) - P(A∩B)

Where the probability P(A) that a student has GPA of 3.5 or better is 0.25, the probability P(B) that a student is enrolled in at least one AP class is 0.16 and the probability P(A∩B) that a student has a GPA of 3.5 or better and is enrolled in at least one AP class is 0.12

So, P(A∪B) is equal to:

P(A∪B) = P(A) + P(B) - P(A∩B)

P(A∪B) = 0.25 + 0.16 - 0.12

P(A∪B) = 0.29

Finally, P(A'∩B') is equal to:

P(A'∩B') = 1 - P(A∪B)

P(A'∩B') = 1 - 0.29

P(A'∩B') = 0.71

5 0

3 years ago

Read 2 more answers

(c). It is well known that the rate of flow can be found by measuring the volume of blood that flows past a point in a given tim

aleksklad [387]

(i) Given that

$V(R) = \displaystyle \int_0^R 2\pi K(R^2r-r^3) \, dr$

when R = 0.30 cm and v = (0.30 - 3.33r²) cm/s (which additionally tells us to take K = 1), then

$V(0.30) = \displaystyle \int_0^{0.30} 2\pi \left(0.30-3.33r^2\right)r \, dr \approx \boxed{0.0425}$

and this is a volume so it must be reported with units of cm³.

In Mathematica, you can first define the velocity function with

v[r_] := 0.30 - 3.33r^2

and additionally define the volume function with

V[R_] := Integrate[2 Pi v[r] r, {r, 0, R}]

Then get the desired volume by running V[0.30].

(ii) In full, the volume function is

$\displaystyle \int_0^R 2\pi K(R^2-r^2)r \, dr$

Compute the integral:

$V(R) = \displaystyle \int_0^R 2\pi K(R^2-r^2)r \, dr$

$V(R) = \displaystyle 2\pi K \int_0^R (R^2r-r^3) \, dr$

$V(R) = \displaystyle 2\pi K \left(\frac12 R^2r^2 - \frac14 r^4\right)\bigg_0^R$

$V(R) = \displaystyle 2\pi K \left(\frac{R^4}2- \frac{R^4}4\right)$

$V(R) = \displaystyle \boxed{\frac{\pi KR^4}2}$

In M, redefine the velocity function as

v[r_] := k*(R^2 - r^2)

(you can't use capital K because it's reserved for a built-in function)

Then run

Integrate[2 Pi v[r] r, {r, 0, R}]

This may take a little longer to compute than expected because M tries to generate a result to cover all cases (it doesn't automatically know that R is a real number, for instance). You can make it run faster by including the Assumptions option, as with

Integrate[2 Pi v[r] r, {r, 0, R}, Assumptions -> R > 0]

which ensures that R is positive, and moreover a real number.

5 0

3 years ago

What is the answer to 4x - 2 ˂ 26

Nat2105 [25]

Answer:

x<7

Step-by-step explanation:

The app Photomath can solve these questions for you, all you have to do is scan it and then it solves it for you! :D

3 0

3 years ago