Help me solve this please, im really bad at stuff like this

Answer:

9

Step-by-step explanation:

b = Brandon

4b=b+27

-b   -b

-------------

3b = 27

----   ----

3      3

b = 9

Brandon is 9 years old.

Answer:

$3735

Step-by-step explanation:

2/5 = 8/20

8/20 + 7/20 = 15/20 = 3/4

3/4*4980 = 3735

Answer: 12%

Step-by-step explanation:

95,000-83,600=11,400

(11,400/95000)(100) = 12%

The percentage reduction in the price of the car is 12%

A percentage is a number or ratio that can be expressed as a fraction of 100. If we have to calculate the percent of a number, divide the number by the whole and multiply by 100. Hence, the percentage means, a part per hundred. The word percent means per 100. It is represented by the symbol “%”

Given here: Original price of car=95000 and Selling price=83600

Thus the reduction in price= 95000-83600

                                            =11400

Thus percentage reduction in the price of the car is

= 11400/95000 × 100

=12%

Hence, The percentage reduction in the price of the car is 12%

Learn more about percentages here:

https://brainly.com/question/29306119

#SPJ2

Answer:

the answer of that is number C

Answer: Damien = 7.5 hours and Caitlyn = 28.5 hours

Step-by-step explanation:

Damien = X -21

Caitlyn = X

2X - 21 = 14

2X = 14 + 21

X = (14+21)/2

X = 7.5

9514 1404 393

Answer:

  4·10 +4·5 = 6·12 -6·2

Step-by-step explanation:

Each outside factor multiplies each inside term.

  4(10 +5) = 6(12 -2)

  4·10 +4·5 = 6·12 -6·2

Given:

If x, y, and z are positive integers, then

[tex]2^x\times 3^y\times 5^z=54000[/tex]

To find:

The value of [tex]x+y+z[/tex].

Solution:

First we need to find the prime factors of 54000.

[tex]54000=2\times 2\times 2\times 2\times 3\times 3\times 3\times 5\times 5\times 5[/tex]

[tex]54000=2^4\times 3^3\times 5^3[/tex]        ...(i)

We have,

[tex]54000=2^x\times 3^y\times 5^z[/tex]        ...(ii)

On comparing (i) and (ii), we get [tex]x=4,y=3,z=3[/tex].

The sum of [tex]x,y,z[/tex] is:

[tex]x+y+z=4+3+3[/tex]

[tex]x+y+z=10[/tex]

Therefore, the value of [tex]x+y+z[/tex] is 10.

Answer:

14

Step-by-step explanation:

The area of a parallelogram is

A = bh where b is the base and h is the height

140 = b*10

Divide each side by 10

140/10 = 10b/10

14 = b

Answer:

8

Step-by-step explanation:

If you add x to the left side of the equation you get positive 1/2x +3=7

you then would subtract 3 from 7 to get 4

this would leave you with 1/2x=4

if you divide 4 by 1/2 you get 8 as the answer.

Given:

The function is:

[tex]f(x)=x^2-x+1[/tex]

To find:

The result of the operation [tex]-f(x)=-(x^2-x+1)[/tex].

Solution:

If [tex]g(x)=-f(x)[/tex], then the graph of f(x) is reflected across the x-axis to get the graph of g(x).

We have,

[tex]f(x)=x^2-x+1[/tex]

The given operation is:

[tex]-f(x)=-(x^2-x+1)[/tex]

So, it will result in a reflection across the x-axis.

Therefore, the correct option is A.

Answer:

A) reflection across the x-axis.

Step-by-step explanation: I took the test

Answer:

[tex]x(2x+y+5) - 2(x\²+xy+5) + y(x + y) = 5x -10 + y\²[/tex]

Step-by-step explanation:

Given

[tex]x(2x+y+5) - 2(x\²+xy+5) + y(x + y)[/tex]

Required

Simplify

We have:

[tex]x(2x+y+5) - 2(x\²+xy+5) + y(x + y)[/tex]

Open brackets

[tex]x(2x+y+5) - 2(x\²+xy+5) + y(x + y) = 2x\²+xy+5x - 2x\²-2xy-10 + xy + y\²[/tex]

Collect like terms

[tex]x(2x+y+5) - 2(x\²+xy+5) + y(x + y) = 2x\²- 2x\²+xy-2xy+ xy+5x -10 + y\²[/tex]

[tex]x(2x+y+5) - 2(x\²+xy+5) + y(x + y) = 5x -10 + y\²[/tex]

Answer:

Incomplete question, but I gave a primer on the hypergeometric distribution, which is used to solve this question, so just the formula has to be applied to find the desired probabilities.

Step-by-step explanation:

The resistors are chosen without replacement, which means that the hypergeometric distribution is used to solve this question.

Hypergeometric distribution:

The probability of x successes is given by the following formula:

[tex]P(X = x) = h(x,N,n,k) = \frac{C_{k,x}*C_{N-k,n-x}}{C_{N,n}}[/tex]

In which:

x is the number of successes.

N is the size of the population.

n is the size of the sample.

k is the total number of desired outcomes.

Combinations formula:

[tex]C_{n,x}[/tex] is the number of different combinations of x objects from a set of n elements, given by the following formula.

[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]

In this question:

12 resistors, which means that [tex]N = 12[/tex]

3 defective, which means that [tex]k = 3[/tex]

4 are selected, which means that [tex]n = 4[/tex]

To find an specific probability, that is, of x defectives:

[tex]P(X = x) = h(x,N,n,k) = \frac{C_{k,x}*C_{N-k,n-x}}{C_{N,n}}[/tex]

[tex]P(X = x) = h(x,12,4,3) = \frac{C_{3,x}*C_{9,4-x}}{C_{12,4}}[/tex]

Step-by-step explanation:

here's the answer to your question

the answer is 1/12

the first rolling a 4 has a 1/6 chance of happening and half of the numbers on the die are odd, so 1/6*1/2=1/12

Answer:

Since [tex]n(1-p) = 3.72 < 10[/tex], the normal curve cannot be used as an approximation to the binomial probability.

100% probability that greater than 26 out of 124 software users will call technical support.

Step-by-step explanation:

Test if the normal curve can be used as an approximation to the binomial probability by verifying the necessary conditions.

It is needed that:

[tex]np \geq 10[/tex] and [tex]n(1-p) \geq 10[/tex]

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

In which [tex]C_{n,x}[/tex] is the number of different combinations of x objects from a set of n elements, given by the following formula.

[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]

And p is the probability of X happening.

Can be approximated to a normal distribution, using the expected value and the standard deviation.

The expected value of the binomial distribution is:

[tex]E(X) = np[/tex]

The standard deviation of the binomial distribution is:

[tex]\sqrt{V(X)} = \sqrt{np(1-p)}[/tex]

Normal probability distribution

Problems of normally distributed distributions can be solved using the z-score formula.

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.

When we are approximating a binomial distribution to a normal one, we have that [tex]\mu = E(X)[/tex], [tex]\sigma = \sqrt{V(X)}[/tex].

Out of 124 software users

This means that [tex]n = 124[/tex]

Assume the probability that a given software user will call technical support is 97%.

This means that [tex]p = 0.97[/tex]

Conditions:

[tex]np = 124*0.97 = 120.28 \geq 10[/tex]

[tex]n(1-p) = 124*0.03 = 3.72 < 10[/tex]

Since [tex]n(1-p) = 3.72 < 10[/tex], the normal curve cannot be used as an approximation to the binomial probability.

Consider the probability that greater than 26 out of 124 software users will call technical support.

The lowest possible probability of those is 27, so, if it is 0, since it is considerably below the mean, 100% probability of being greater. We have that:

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

[tex]P(X = 27) = C_{124,27}.(0.97)^{27}.(0.03)^{97} = 0[/tex]

1 - 0 = 1

100% probability that greater than 26 out of 124 software users will call technical support.

Answer:

x = 4[tex]\sqrt{2}[/tex]

Step-by-step explanation:

Pytago:

x[tex]x^{2} +7^{2} = 9^{2} \\\\x = \sqrt{9^{2} - 7^{2} } x = 4\sqrt{2}[/tex]

Answer:

It is the first one, The total drop in temperature, −20∘F, divided by 4 hours equals −5∘F per hour. The temperature dropped 5∘F each hour.

Step-by-step explanation:

Answer:

The projectile will reach a height of 96 feet after about 0.84 seconds as well as after about 7.16 seconds.

Step-by-step explanation:

The height of a projectile fired upward is given by the formula:

[tex]\displaystyle s = v_{0} t - 16t^2[/tex]

Where s is the height in feet, v₀ is the initial velocity, and t is the time in seconds.

Given a projectile with an initial velocity of 128 ft/s, we want to determine how long it will take the projectile to reach a height of 96 feet.

In other words, given that v₀ = 128, find t such that s = 96.

Substitute:

[tex](96) = (128)t-16t^2[/tex]

This is a quadratic. First, we can divide both sides by -16:

[tex]-6 = -8t+t^2[/tex]

Isolate the equation:

[tex]t^2 - 8t + 6 = 0[/tex]

The equation isn't factorable, so we can consider using the quadratic formula:

[tex]\displaystyle t = \frac{-b\pm\sqrt{b^2 - 4ac}}{2a}[/tex]

In this case, a = 1, b = -8, and c = 6. Substitute:

[tex]\displaystyle t = \frac{-(-8)\pm\sqrt{(-8)^2-4(1)(6)}}{2(1)}[/tex]

Simplify:

[tex]\displaystyle t = \frac{8\pm\sqrt{40}}{2} = \frac{8\pm 2\sqrt{10}}{2} = 4\pm \sqrt{10}[/tex]

Hence, our two solutions are:

[tex]\displaystyle t = 4+\sqrt{10} \approx 7.16\text{ or } t= 4-\sqrt{10} \approx 0.84[/tex]

So, the projectile will reach a height of 96 feet after about 0.84 seconds as well as after about 7.16 seconds.

Answer:

16[tex]\frac{3}{4}[/tex]

Step-by-step explanation:

Step-by-step explanation:

the guys is wrong i checked

Answer:

900

Step-by-step explanation:

Given that :

Enrollment declined by 20% from between September 1991 to September 1994

This means there was a reduction in enrollment ;

Enrollment in September 1994 = 720

Enrollment in September 1991 = x

Hence,

Enrollment in 1994 = (1 - decline rate ) * enrollment in 1991

720 = (1 - 20%) * x

720 = (1 - 0.2) * x

720 = 0.8x

720 / 0.8 = 0.8x/0.8

900 = x

Hence, Enrollment in September 1991 = 900 enrollments

Answer:

a. 16 slug b. 3.2 ft

Step-by-step explanation:

a. Total mass of the rod

Since the linear density at a point of the rod,λ varies directly as the third power of the measure of the distance of the point form the end, x

So, λ ∝ x³

λ = kx³

Since the linear density λ = 2 slug/ft at then center when x = L/2 where L is the length of the rod,

k = λ/x³ = λ/(L/2)³ = 8λ/L³

substituting the values of the variables into the equation, we have

k = 8λ/L³

k = 8 × 2/4³

k = 16/64

k = 1/4

So, λ = kx³ = x³/4

The mass of a small length element of the rod dx is dm = λdx

So, to find the total mass of the rod M = ∫dm = ∫λdx we integrate from x = 0 to x = L = 4 ft

M = ∫₀⁴dm

= ∫₀⁴λdx

= ∫₀⁴(x³/4)dx

= (1/4)∫₀⁴x³dx

= (1/4)[x⁴/4]₀⁴

= (1/16)[4⁴ - 0⁴]

= (256 - 0)/16

= 256/16

= 16 slug

b. The center of mass of the rod

Let x be the distance of the small mass element dm = λdx from the end of the rod. The moment of this mass element about the end of the rod is xdm =  λxdx = (x³/4)xdx = (x⁴/4)dx.

We integrate this through the length of the rod. That is from x = 0 to x = L = 4 ft

The center of mass of the rod x' = ∫₀⁴(x⁴/4)dx/M where M = mass of rod

= (1/4)∫₀⁴x⁴dx/M

= (1/4)[x⁵/5]₀⁴/M

= (1/20)[x⁵]₀⁴/M

= (1/20)[4⁵ - 0⁵]/M

= (1/20)[1024 - 0]/M

= (1/20)[1024]/M

Since M = 16, we have

x' =  (1/20)[1024]/16

x' = 64/20

x' = 3.2 ft

Answer:

30.03

Step-by-step explanation:

[(33.7)² - (15.3)²]^½

= [1135.69 - 234.09]^½

= [901.6]^½

= 30.02665483

= 30.03 (4sf)

Answer:

3645

Step-by-step explanation:

f(1)=5

f(2)=3*5=15.

f(3)=45, basically it's a geometric sequence with formula an=5*(3)^(n-1). The 7th term is 5*(3)^6=3645

Answer:

Let x = the number of ounces of Solution A

Let y = the number of ounces of Solution B

x + y = 180        y = 180 - x

.60x + .85y = .75(180)

.60x + .85y = 135      Multiply both sides of the equation by 100 to remove the decimal points.

60x + 85y = 13500

60x + 85(180 - x) = 13500

60x + 15300 - 85x = 13500

-25x = -1800

x = 72ounces

y = 180 - 72

y = 108 ounces          

Step-by-step explanation:

Wyzant (ask an expert) solution on their website.

Answer:

Step-by-step explanation:

Answer:

5/12

Step-by-step explanation:

Heads: 1/2

Number greater than 1

A dice has 6 sides. 5 are greater than 1

The probability is 5/6

P(heads and a die greater than 1) = 1/2 * 5/6 = 5/12 or a little less than 1/2

Answer:

I think you can go with:

The margin of error is equal to half the width of the entire confidence interval.

so  try .74 ±   =   [ .724 , .756] as the confidence interval

Step-by-step explanation:

Answer: hello from the question the volume of tank = 6000 gallons while the value in the Torricelli's equation = 5000 hence I resolved your question using the Torricelli's law equation

answer:

1) a) -180  gallons/minute ,

  b)  -160 gallons/minute

  c)  -120 gallons/minute

  d) 0

2) The water is flowing out fastest when t = 5 min

3) The water is flowing out slowest after t = 20 mins

Step-by-step explanation:

Volume of tank = 5000 gallons

Time to drain = 50 minutes

Volume of water remaining after t minutes by Torricelli's law

V = 5000 ( 1 - [tex]\frac{1}{50}t[/tex] )^2 ----- ( 1 )

1) Determine the rate at which water is draining from the tank

First step : differentiate equation 1 using the chain rule to determine the rate at which water is draining from the tank

V' = [tex]-10000[ ( 1 - \frac{1}{50}t ) (\frac{1}{50}) ][/tex]

a) After t = 5minutes

V' = - 10000[ ( 1 - 0.1 ) * ( 0.02 ) ]

   = -180  gallons/minute

b) After t = 10 minutes

V' = - 10000[ ( 1 - 0.2 ) * ( 0.02 ) ]

   = - 160 gallons/minute

c) After t = 20 minutes

V' = - 10000 [ ( 1 - 0.4 ) * ( 0.02 ) ]

   = -120 gallons/minute

d) After t = 50 minutes

V' = - 10000 [ ( 1 - 1 ) * ( 0.02 ) ]

   = 0 gallons/minute

2) The water is flowing out fastest when t = 5 min

3) The water is flowing out slowest after t = 20 mins  because no water flows out after 50 minutes

Answer:

C. repeating back what the customer says