answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Lyrx [107]
2 years ago
7

Half of Ethan's string is equal to 2/3 of Kayla's string. The total length of their strings is 10 feet. How much longer is Ethan

's string than Kayla's? Drawing

Mathematics
2 answers:
IgorC [24]2 years ago
5 0

Answer:

Ethan's string is =\frac{10}{7} feet longer than Kayla's string.

Step-by-step explanation:

Let Ethan's string = x feet

and Kayla's string = y feet

According to question,

Half of Ethan's string is equal to 2/3 of Kayla's string that is,

\frac{1}{2}x=\frac{2}{3}y

\Rightarrow x=\frac{4}{3}y   ..............(1)

Also,The total length of their strings is 10 feet that is,

x+y=10

Put value of x from (1),

\frac{4}{3}y+y=10

Solving for y, we get,

\Rightarrow y(\frac{4}{3}+1)=10

\Rightarrow y(\frac{4+3}{3})=10

\Rightarrow y(\frac{7}{3})=10

\Rightarrow y=\frac{10 \times 3}{7}

\Rightarrow y=\frac{30}{7}

Thus,  Length of Kayla's string is \frac{30}{7} feet.

and Put value of y in (1) to get value of x,

\Rightarrow x=\frac{4}{3} \times \frac{30}{7}

\Rightarrow x=\frac{40}{7}

Thus,  Length of Ethan's string is \frac{40}{7} feet.

Length of Ethan's string is longer than Kayla's string = Length of Ethan's string-Length of Kayla's string.

=\frac{40}{7}-\frac{30}{7}

=\frac{10}{7}

Thus, Ethan's string is =\frac{10}{7} feet longer than Kayla's string.


german2 years ago
3 0

Answer: \frac{10}{7} meters


Step-by-step explanation:

Let x be the length of Kaya's string and y be the length of Ethan's string

Then According to the question, we have the following equations

\frac{1}{2}y=\frac{2}{3}x\\\Rightarrow\ y=\frac{4}{3}x......(1)\\x+y=10....(2)

Substitute the value of y from (1) in (2), we get

\frac{4}{3}x+x=10\\\Rightarrow\frac{4x+3x}{3}=10\\\Rightarrow\ \frac{7x}{3}=10\\\Rightarrow\ x=\frac{30}{7}

The length of Kaya's string =\frac{30}{7} feet

The length of Ethan's string =\frac{4}{3}\times\frac{30}{7}=\frac{40}{7} meters

The difference in their lengths=\frac{40}{7}-\frac{30}{7}=\frac{10}{7}

Hence, Ethan's string is \frac{10}{7} meters longer than the Kaya's string.



You might be interested in
A piece of paper is to display ~128~ 128 space, 128, space square inches of text. If there are to be one-inch margins on both si
Grace [21]

Answer:

The dimensions of the smallest piece that can be used are: 10 by 20 and the area is 200 square inches

Step-by-step explanation:

We have that:

Area = 128

Let the dimension of the paper be x and y;

Such that:

Length = x

Width = y

So:

Area = x * y

Substitute 128 for Area

128 = x * y

Make x the subject

x = \frac{128}{y}

When 1 inch margin is at top and bottom

The length becomes:

Length = x + 1 + 1

Length = x + 2

When 2 inch margin is at both sides

The width becomes:

Width = y + 2 + 2

Width = y + 4

The New Area (A) is then calculated as:

A = (x + 2) * (y + 4)

Substitute \frac{128}{y} for x

A = (\frac{128}{y} + 2) * (y + 4)

Open Brackets

A = 128 + \frac{512}{y} + 2y + 8

Collect Like Terms

A = \frac{512}{y} + 2y + 8+128

A = \frac{512}{y} + 2y + 136

A= 512y^{-1} + 2y + 136

To calculate the smallest possible value of y, we have to apply calculus.

Different A with respect to y

A' = -512y^{-2} + 2

Set

A' = 0

This gives:

0 = -512y^{-2} + 2

Collect Like Terms

512y^{-2} = 2

Multiply through by y^2

y^2 * 512y^{-2} = 2 * y^2

512 = 2y^2

Divide through by 2

256=y^2

Take square roots of both sides

\sqrt{256=y^2

16=y

y = 16

Recall that:

x = \frac{128}{y}

x = \frac{128}{16}

x = 8

Recall that the new dimensions are:

Length = x + 2

Width = y + 4

So:

Length = 8 + 2

Length = 10

Width = 16 + 4

Width = 20

To double-check;

Differentiate A'

A' = -512y^{-2} + 2

A" = -2 * -512y^{-3}

A" = 1024y^{-3}

A" = \frac{1024}{y^3}

The above value is:

A" = \frac{1024}{y^3} > 0

This means that the calculated values are at minimum.

<em>Hence, the dimensions of the smallest piece that can be used are: 10 by 20 and the area is 200 square inches</em>

3 0
2 years ago
Li wants to add these items to her suitcase: a hairdryer (1.25 lb), a hand-held video game (0.6 lb), an extra video game (0.25 l
lbvjy [14]
Add some of them or all of them to your sum of 47.75, if either or exceeds the limit then that is what left out.
7 0
2 years ago
Read 2 more answers
Where does the helix r(t) = cos(πt), sin(πt), t intersect the paraboloid z = x2 + y2? (x, y, z) = What is the angle of intersect
Colt1911 [192]

Answer:

Intersection at (-1, 0, 1).

Angle 0.6 radians

Step-by-step explanation:

The helix r(t) = (cos(πt), sin(πt), t) intersects the paraboloid  

z = x2 + y2 when the coordinates (x,y,z)=(cos(πt), sin(πt), t) of the helix satisfy the equation of the paraboloid. That is, when

\bf (cos(\pi t), sin(\pi t), t)

But  

\bf cos^2(\pi t)+sin^2(\pi t)=1

so, the helix intersects the paraboloid when t=1. This is the point

(cos(π), sin(π), 1) = (-1, 0, 1)

The angle of intersection between the helix and the paraboloid is the angle between the tangent vector to the curve and the tangent plane to the paraboloid.

The <em>tangent vector</em> to the helix in t=1 is

r'(t) when t=1

r'(t) = (-πsin(πt), πcos(πt), 1), hence

r'(1) = (0, -π, 1)

A normal vector to the tangent plane of the surface  

\bf z=x^2+y^2

at the point (-1, 0, 1) is given by

\bf (\frac{\partial f}{\partial x}(-1,0),\frac{\partial f}{\partial y}(-1,0),-1)

where

\bf f(x,y)=x^2+y^2

since

\bf \frac{\partial f}{\partial x}=2x,\;\frac{\partial f}{\partial y}=2y

so, a normal vector to the tangent plane is

(-2,0,-1)

Hence, <em>a vector in the same direction as the projection of the helix's tangent vector (0, -π, 1) onto the tangent plane </em>is given by

\bf (0,-\pi,1)-((0,-\pi,1)\bullet(-2,0,-1))(-2,0,1)=(0,-\pi,1)-(-2,0,1)=(2,-\pi,0)

The angle between the tangent vector to the curve and the tangent plane to the paraboloid equals the angle between the tangent vector to the curve and the vector we just found.  

But we now

\bf (2,-\pi,0)\bullet(0,-\pi,1)=\parallel(2,-\pi,0)\parallel\parallel(0,-\pi,1)\parallel cos\theta

where  

\bf \theta= angle between the tangent vector and its projection onto the tangent plane. So

\bf \pi^2=(\sqrt{4+\pi^2}\sqrt{\pi^2+1})cos\theta\rightarrow cos\theta=\frac{\pi^2}{\sqrt{4+\pi^2}\sqrt{\pi^2+1}}=0.8038

and

\bf \theta=arccos(0.8038)=0.6371\;radians

7 0
2 years ago
If y ∝ 1∕x and y = –2 when x = 14, find the equation that connects x and y.
crimeas [40]

C. y= -28/x

y=k/x

cross multiply

k= y×x

k = -2×14

k = -28

y = -28/x [ equation connecting x and y]

8 0
2 years ago
Which translation maps the vertex of the graph of the function f(x) = x2 onto the vertex of the function g(x) = x2 – 10x +2?
zhuklara [117]

Answer:

  • <em>The translation that maps the vertex of the graph of the function f(x) = x² onto the vertex of the function g(x) = x² - 10x + 2 is </em><u>5 units to the right and 23 units down.</u>

Explanation:

<u>1) </u><u>Vertex form</u><u> of the function that represents a parabola.</u>

The general form of a quadratic equation is Ax² + Bx + C = 0, where A ≠ 0, and B and C may be any real number. And the graph of such equation is a parabola with a minimum or maximum value at its vertex.

The vertex form of the graph of such function is: A(x - h)² + k

Where, A a a stretching factor (in the case |A| > 1) or compression  factor (in the case |A| < 1) factor.

<u>2) Find the vertex of the first function, f(x) = x²</u>

This is the parent function, for which, by simple inspection, you can tell h = 0 and k = 0, i.e. the vertex of f(x) = x² is (0,0).

<u>3) Find teh vertex of the second function, g(x) = x² -10x + 2</u>

The method is transforming the form of the function by completing squares:

  • Subtract 2 from both sides: g(x) - 2 = x² - 10x

  • Add the square of half of the coefficient of x (5² = 25) to both sides: g(x) - 2 + 25 = x² - 10x + 25

  • Simplify the left side and factor the right side: g(x) + 23 = (x - 5)²

  • Subtract 23 from both sides: g(x) = (x - 5)² - 23

That is the searched vertex form: g(x) = (x - 5)² - 23.

From that, using the rules of translation you can conclude immediately that the function f(x) was translated 5 units horizontally to the right and 23 units vertically downward.

Also, by comparison with the verex form A(x - h)² + k, you can conclude that the vertex of g(x) is (5, -23), and that means that the vertex (0,0)  was translated 5 units to the right and 23 units downward.

5 0
2 years ago
Other questions:
  • Suppose you earned 7t -1 dollars on monday and 8t + 5 on tuesday. what are your total earnings? simplify your answer
    8·1 answer
  • Michael pays $30 to enter a state fair, plus $4 for each ride. Which of the following equations represents his total cost? A. y=
    13·2 answers
  • In the diagram, the measurements that are labeled are known, while the other measurements are unknown. Which measurement of acut
    8·1 answer
  • Samantha opened a savings account and deposited $8192. The account earns 10% in interest annually. She makes no further deposits
    14·2 answers
  • Quadrilateral ABCD is similiar to quadrilateral EFGH. The lengths of the three longest sides in quadrilateral ABCD are 24 feet,
    14·2 answers
  • what is the simplified form of the following expression? Assume x is greater than or equal to 0 and y is greater than or equal t
    13·2 answers
  • Joe wants to enlarge the rectangular pumpkin patch located on his farm. The pumpkin patch is currently 40 meters wide and 60 met
    9·1 answer
  • A. The average yearly salary of a lawyer is $24 thousand less than twice that of an architect.
    12·1 answer
  • Maya can run 18 miles in 3 hours, and she can bike 18 miles in 2 hours.
    13·1 answer
  • The diameter of the sun is about 1.4x10^6 km. The diameter of the planet Mercury is about 5000 km. What is the approximate ratio
    10·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!