if y varies directly as the square if x. If y=27 when x=3, find x when y=81?

Answers

Answer 1

Answer:

x = 3[tex]\sqrt{3}[/tex]

Step-by-step explanation:

Given y varies directly as x², then the equation relating them is

y = kx² ← k is the constant of variation

To find k use the condition y = 27 when x = 3 , then

27 = k × 3² = 9k ( divide both sides by 9 )

3 = k

y = 3x² ← equation of variation

When y = 81, then

81 = 3x² ( divide both sides by 3 )

27 = x² ( take the square root of both sides )

x = [tex]\sqrt{27}[/tex] = [tex]\sqrt{9(3)}[/tex] = 3[tex]\sqrt{3}[/tex]


Related Questions

pls answer if you can i need the answer right away

Answers

Answer:

What’s the question?

Step-by-step explanation:

??? where’s the question

Keiko sold t-shirts at a festival. She made $4 for each t-shirt she sold. Her expenses were $25. If she made a profit of $71, how many t-shirts did she sell?

Answers

Answer:

She had sold 24 shirts.

Answer:

24 shirts.

Step-by-step explanation:

Let the number of shirt she sold = x.

4x - 25 = 71

4x = 96

x = 24.

plzzzzzzzzzzzzzzzzzzzzzzz

Answers

Option C. Please mark me as brainliest.

NEED HELP QUICK <3

140 is what percent less than 160?

Answers

Answer:

Step-by-step explanation:

Step 1: We make the assumption that 160 is 100% since it is our output value.

Step 2: We next represent the value we seek with x.

Step 3: From step 1, it follows that 100%=160

Step 4: In the same vein, = x%=140​.

Step 5: This gives us a pair of simple equations:

100%=160(1)​.

x%=140(2)​.

Step 6: By simply dividing equation 1 by equation 2 and taking note of the fact that both the LHS

(left hand side) of both equations have the same unit (%); we have

100% / x% = 160 / 140

Step 7: Taking the inverse (or reciprocal) of both sides yields

x% / 100% = 140 / 160

x% = 87.5%

therefore, 140 is 87.5% of 160

We obtain that 140 is 12.5% percent less than 160.

What is the percentage?

A percentage is a value per hundredth. Percentages can be converted into decimals and fractions by dividing the percentage value by a hundred.

Given, 140 is some percent less than 160 to obtain this we'll subtract (140/160)×100% from 100% which is,

= 100% - (140/160)×100%.

= 100% - 87.5%.

= 12.5%

learn more about percentages here :

https://brainly.com/question/24159063

#SPJ2

tell whether the given ordered pair is a solution of the equation y = -2 + 5;(2,1)

Answers

Note: your equation is a little bit unclear. Thus, I am assuming that

y = 2x+5

Anyway, the procedure remains the same. It would anyways clear your concept.

Answer:

We conclude that the ordered pair (2, 1) is a solution.

Step-by-step explanation:

Given the equation

[tex]y = -2x+5[/tex]

Check for point (2, 1)

substituting the point (2, 1) in the equation to check whether the ordered point satisfies the equation or not.

[tex]y = -2x+5[/tex]

plug in x = 2 and y = 1

1 = -2(2)+5

1 = -4+5

1 = 1

R.H.S = L.H.S

TRUE

Therefore, the given ordered pairs satisifes the equation.

Hence, we conclude that the ordered pair (2, 1) is a solution.

a school has 1800 students 55 %of the students of girls. how many boys are in the school?​

Answers

Answer:

810 boys

Step-by-step explanation:

1800 students and 55% are girls.

100%-55%=45%

1800*0.45 = 810

1800*0.55 = 990

So there are 990 girls and 810 boys.

Hope this helps :)

Please answer correctly !!!!!!!!!!!!! Will mark Brianliest !!!!!!!!!!!!!!!!!!

Answers

Answer:

7

Step-by-step explanation:

Pythagorean theorem. 24^2+b^2=25^2

Simplify

576+b^2=625

b^2=49

b=7

Maria invests her $150 for 2 years at 4% per year compound interest.
A) Calculate the exact amount Maria has at the end of 2 years.
Maria continues to invest her money at 4% per year compound interest.
After 20 years she has $328.67.
i) Calculate exactly how much more this is than $150 invested for 20 years at
simple interest.
(ii) Calculate $328.67 as a percentage of $150.

Answers

Step-by-step explanation:

A)At the end of 2years compound interest=$150(1+4/100)²=$162.24

i) Amount difference=$328.67-{($150×4×20/100)+$150}

=$328.67-$270=$58.67

ii)328.67/150×100%=121.73%

Traveling upstream (against the current) in a boat, you can travel 35 miles in 7 hours. It
takes half the time (3.5 hours) to travel the same distance downstream (with the
current). Find the speed of the current.

Answers

Answer:

The speed of the current is 2.5 miles per hour

Step-by-step explanation:

Systems of Equations

Let's call:

B = velocity of the boat

C = velocity of the current

When traveling upstream, the current is against the boat thus the relative velocity is B-C.

The distance is the product of the velocity by the time. Since the boat takes 7 hours to travel 35 miles upstream, thus:

d=(B-C)*7=35

Dividing by 7:

B - C = 5       [1]

When traveling downstream, the current and the boat are collaborative and the relative velocity is B+C. The travel takes now 3.5 hours, thus:

d=(B+C)*3.5=35

Dividing by 3.5:

B + C = 10       [2]

Subtracting [2] - [1]:

2C = 5

C = 5/2 = 2.5

The speed of the current is 2.5 miles per hour

Kate received $15 from her Nana on her birthday. Kate used this money to open a bank account, and added money each week as shown in the table. Interpret the y-intercept of the graph of this function.

Answers

Answer:

15

Step-by-step explanation:

x = time in weeks

y= dollars

so once x hits 0 they corresponding y will be the y intercept.

Camille is getting older and feels like she should donate her collection of
stuffed animals to children who are less fortunate. She has 45 stuffed
cats and 18 stuffed dogs, which she wants to divide into identical groups
with no stuffed animals left over. What is the greatest number of groups
Camille can place her stuffed animals into? *
Plz help ASAP

Answers

Answer:

Answer is in photo

Step-by-step explanation:

If p = 3sec theta and q= 3 tan^2 theta - 1, then find p-q. ​

Answers

Answer:

[tex]p - q = 3 \sec\theta - (3 { \tan}^{2} \theta - 1) \\ = 3 \sec \theta - 3 { \tan}^{2} \theta + 1 \\ from \: identities \: \: { \tan }^{2} \theta + 1 = { \sec }^{2} \theta \\ = 3 { \sec } \theta - 3( { \sec }^{2} \theta - 1) + 1 \\ = 3 \sec\theta - 3 { \sec}^{2} \theta + 3 + 1 \\ = - 3 { \sec }^{2} \theta + 3 \sec\theta + 4 \\ = - 3( { \sec}^{2} \theta - \sec \theta - \frac{4}{3} )[/tex]

Simplify the expression below
(-4x^3+ 2x^2 - 3x)

+

(x^3+ 2x^2+3x)

Answers

Answer: = -3x^3 + 4x^2

Step-by-step explanation:

Answer:

-3x^3 + 4x^2

lmk if this helps

five waters bottles and 2 sodas cost $5.57

Answers

Answer:

ok

Step-by-step explanation:

Exercises that are _________ in nature are those that make your muscles use oxygen to perform

a) Aerobi

b) Anaerobic​

Answers

Answer:

Aerobic

Step-by-step explanation:

Oxygen = aerobic

no oxygen = anaerobic

aerobic since its using oxygen

given: rectangle JKLM

prove: JL = MK

Answers

Need more info attach a pic

Answer:

(In order, top to bottom. )

Definition of a rectangle

opposite sides of a rectangle are congruent

reflexive property of congruence

SAS congruence postulate

Step-by-step explanation:

Parallelogram JKLM is a rectangle and by definition of a rectangle, ∠JML

and ∠KLM are right angles, ∠JML ≅ ∠KLM because, all right angles are

congruent, ≅ because opposite sides of a parallelogram are congruent, and ≅ by reflective property of congruence. By the SAS

congruence postulate, ΔJML ≅ ΔKLM.

congruent parts of congruent triangles are congruent, ≅

The given quadrilateral is a parallelogram, that have interior angles that are right angles, therefore, the figure has the properties of a rectangle, and

parallelograms including the length of opposite sides are equal, all right angles are congruent and equal to 90° and the length of a side is equal to itself by reflexive property, & ≅

The Side-Angle-Side SAS postulate states that if two sides and an included

angle of one triangle are congruent to the corresponding two of sides and

included angle of another triangle, the two triangles are congruent.

HELP ASAAAAAP EXPLAIIINNN

Answers

Answer:

dhdhrjfidgegehfr fhfn fhc fn dncc c. f byn

Step-by-step explanation:

h(t) = -16t² + 64t + 32

When h(t) = 80, -16t² + 64t + 32 = 80.

=> 16t² - 64t + 48 = 0

=> t² - 4t + 3 = 0

=> (t - 1)(t - 3) = 0

=> t = 1 or t = 3.

Hence the difference between the times is 2 seconds. (B)

Let f be the function defined by f(x) = –x^3 – x. If g represents the inverse of f, what is g′(10)?

Answers

Answer:

[tex]\displaystyle g'(10)=\frac{1}{-13}=-\frac{1}{13}[/tex]

Step-by-step explanation:

The Derivative of the Inverse Function

Let f(x) be a real invertible function, and g(x) the inverse function of f(x), i.e.,:

[tex]g(x)=f^{-1}(x)[/tex]

We can calculate the derivative of the inverse function even if we don't have the inverse function explicitly computed. We use the formula:

[tex]\displaystyle g'(x)=\frac{1}{f'(g(x))}[/tex]

We need to find the value of g'(10) when:

[tex]f(x)=-x^3-x[/tex]

Substituting:

[tex]\displaystyle g'(10)=\frac{1}{f'(g(10))}[/tex]

We don't have the value of g(10) but we can guess its value since the inverse functions f and g satisfy:

if y=f(x), then g(y)=x, thus we need to find a value of x that produces a value of f(x)=10.

We can easily find that x=-2:

[tex]f(-2)=-(-2)^3-(-2)=8+2=10.[/tex]

Thus, g(10)=-2

Now we find:

[tex]f'(x)=-3x^2-1[/tex]

[tex]f'(-2)=-3(-2)^2-1[/tex]

[tex]f'(-2)=-3*4-1=-13[/tex]

Thus, finally:

[tex]\displaystyle g'(10)=\frac{1}{-13}=-\frac{1}{13}[/tex]

Sean has a beginning balance of $328.15 in his account. He writes checks for the following amounts: $20.75, $43.58,
$30.45, and $29.72. What is the new balance in Sean's account?
$14.75

$203.65

$124.50

$307.40


Answers

Answer:

The new balance in Sean's account is $203.65

Step-by-step explanation:

The initial balance in Sean's account is $328.15. Then he writes checks for the amounts $20.75, $43.58, $30.45, and $29.72.  

The sum of his checks is $20.75 + $43.58 + $30.45 + $29.72 = $124.5

The new balance in Sean's account is the initial balance minus the sum of the amounts of the checks he wrote:

Final balance = $328.15 - $124.5 = $203.65

The new balance in Sean's account is $203.65

sorry if it’s blurry

Answers

Answer:

im blind

Step-by-step explanation:

im really sorry i cant see anything

Answer:

It is A or 3.9

Step-by-step explanation:

PLEASE GIVE BRAINLIEST

its just the square route.

SOLVE FOR X
X/3 + x-1/4 = 2+X
show (or describe every step)
the x-1/4 is ONE fraction, not a variable minus 1/4.

Answers

Answer:

Step-by-step explanation:

Thank you for the note. You show what you want like this.

X/3 + (x - 1)/4 = 2+X         Multiply both sides by 12.

[tex]\frac{12*x}{3} + \frac{12*(x -1)}{4} = 12(x + 2)[/tex]

Now take mini steps.

1. Divide 3 into 12

4x

2. Divide 4 into 12

3(x - 1)

========================

Here's what you have.

4x + 3(x - 1) = 12(x + 2)                        Remove the brackets.

4x + 3x - 3 = 12x + 24                         Combine like terms

7x - 3 = 12x + 24                                 Subtract 7x from both sides.

- 3 = 12x - 7x +24

-3 = 5x + 24                                        Subtract 24 from both sides.

-27 = 5x                                              Divide by 5

x = -5.4

anna has a 12 quarter 4 dimes and 11 nickel in her piggy bank how much money is in the bank

Answers

Answer:

$3.95

Step-by-step explanation:

12*0.25=3

4*0.10=0.40

11*0.05=0.55

3+0.40+0.55=$3.95

Answer:

$3.95

Step-by-step explanation:

12q+4d+11n

PLSPLSPLSPLS I NEED HELPPPPPPPP

Answers

Answer:

huh?

Step-by-step explanation:

Because of a problem in the program, the timer in a video player did not begin counting until the video had been playing for several seconds. The player began counting at 0 seconds, even though the video had already played 190 frames. The video plays 25 frames per second.
How many frames had the video already played when the time was equal to -3 2/5?

Answers

Answer:

105

Step-by-step explanation:

t = 0

frame = 190

so it means, the video has 190 before the timer start counting

speed 25 fps

-------

t = -3 2/5 s = -17/5 s

frame = ?

with the rate of 25 fps

it gain 25 x -17/5 = 85 frame.

so the video at that time has already played

190-85 = 105 frame

You purchase 3 action figures per week. You have 27 action figures, which is 60% of the total number of action figures you need to complete your collection. How many weeks until your collection is complete?

Answers

27/.6=45 total in collection
45-27=18
18/3 per week=6 weeks

Aisha needs to be at least 48 inches tall to ride the colossal coaster at the amusement park. If she grows 5 inches during the next year, Aisha will still not be tall enough to ride. In the context of this situation, what does the inequality x less-than 43 represent? After next year, Aisha still needs to grow 43 more inches to ride. Aisha is less than 43 inches tall right now. Aisha needs to grow 43 more inches to ride. Aisha is at least 43 inches tall now.

Answers

Answer:

B

Step-by-step explanation:

right on edge 2020

Answer: i think it is b correct me if i am wrong

Step-by-step explanation:

What is the length of the hypotenuse of the triangle when x= 12?
6x+4
5x
The length of the hypotenuse is about
(Round to the nearest tenth as needed.)

Answers

Answer:

The length of the hypotenuse: c = 96.8 units

Step-by-step explanation:

Given the sides

a = 6x+4b = 5xc = hypotenuse = ?

Given that the x = 12

so

a = 6x+4 = 6(12)+4 = 76b = 5x = 5(12) = 60

Pythagorean Theorem:

For a right angled triangle with sides 'a' and 'b', the hypotenuse 'c' is defined as:

[tex]c=\sqrt{a^2+b^2}[/tex]

substituting a = 76 and b = 60

[tex]c=\sqrt{76^2+60^2}[/tex]

[tex]c=4\sqrt{586}[/tex]

[tex]c = 96.8[/tex] units

Therefore, the length of the hypotenuse: c = 96.8 units

answer this pls pls pls pls pls

Answers

Answer:

1= 0.25feet per 1 second

2.= 120 seconds

3. 72 seconds or 1 minute 12 seconds

Step-by-step explanation:

1.= 2/8=1/4=.25

2.= 50-20=30

30/.25=120

3.= 18 feet/.25 feet= 72 seconds

Answer:

1= 0.25feet per 1 second

2.= 120 seconds

3. 72 seconds or 1 minute 12 seconds

Step-by-step explanation:

Mr. Verrengia bought some math supplies at the local math depot. He
doesn’t remember how much money the items cost, but knows that
the 5% sales tax came to $1.25. How much money did he spend on the
math supplies before tax?
I need to know quick!

Answers

Answer:

6.25

Step-by-step explanation:

Great things great things

Answers

Answer:

Heeeheeeeheee

Step-by-step explanation:

So right

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