A boat covers 25 km upstream and 44 km downstream in t hours. Also, it covers 15 km upstream and 22 km downstream in 5 hours. Find the speed of the boat in still water and that of the stream.​

Answers

Answer 1

9514 1404 393

Answer:

  boat speed: (7t -95)/(6t² -110t +500)

  stream speed: (37t -345)/(6t² -110t +500)

Step-by-step explanation:

The relation between time, speed, and distance is ...

  time = distance/speed

The boat speed (b) is added to the stream speed (s) going downstream. The stream speed is subtracted going upstream. The given relations tell us ...

  25/(b-s) +44/(b+s) = t

  15/(b-s) +22/(b+s) = 5

This gives us 2 equations in 3 unknowns, so we can only provide a solution in terms of one of the unknowns. Since we are asked for the speeds, they will be provided in terms of t.

Subtracting the first equation from 2 times the second gives ...

  2(15/(b-s) +22/(b+s)) -(25/(b-s) +44/(b+s)) = 2(5) -(t)

  5/(b-s) = 10 -t

  5/(10 -t) = b -s

Substituting for b-s in the second equation gives ...

  15/(5/(10-t)) +22/(b+s) = 5

  30 -3t +22/(b+s) = 5

  22/(b+s) = 3t -25

  22/(3t -25) = b+s

Adding the equations for the sum and difference of speeds, we get ...

  (b-s) +(b+s) = 5/(10-t) +22/(3t -25)

  2b = (5(3t -25) +22(10 -t))/((10-t)(3t-25)) = (95 -7t)/((10-t)(3t-25))

  b = (7t -95)/(6t² -110t +500)

Subtracting the equations for sum and difference of speeds, we get ...

  (b+s) -(b-s) = 22/(3t -25) -5/(10 -t)

  2s = (22(10-t) -5(3t -25))/((10-t)(3t-25))

 s = (37t -345)/(6t² -110t +500)

__

The speed of the boat in still water is (7t -95)/(6t² -110t +500) km/h.

The speed of the stream is (37t -345)/(6t² -110t +500) km/h.

__

Note that these solutions only make sense for values of t between 25/3 and 345/37, approximately 8.33 < t < 9.32. For t=9 hours, the boat speed is 8 km/h and the stream speed is 3 km/h.


Related Questions

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A=√18-√8+√50
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Answers

Answer:

6√2

Step-by-step explanation:

A=3√2-2√2+5√2

A=6√2

Answer:

6√2

Step-by-step explanation:

A=√18-√8+√50 = √9√2 - √4√2 + √2√25, or A = (√2)(3 - 2 + 5) = 6√2

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B) pi/6, 5pi/6
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Answer:

A

Step-by-step explanation:

We want to solve the equation:

[tex]2\sin^2(x)=\sin(x)[/tex]

For the interval [0, 2π).

First, we can move all the terms to one side. Start off by subtracting sin(x) from both sides:

[tex]2\sin^2(x)-\sin(x)=0[/tex]

We can factor:

[tex]\sin(x)\left(2\sin(x)-1\right)=0[/tex]

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[tex]\sin(x)=0\text{ or } 2\sin(x)-1=0[/tex]

Solve for each case:

[tex]\displaystyle \sin(x)=0\text{ or } \sin(x)=\frac{1}{2}[/tex]

Use the unit circle to solve:

[tex]\displaystyle x=\left\{0, \frac{\pi}{6},\frac{5\pi}{6}, \pi\right\}[/tex]

Hence, our answer is A.

*Please note that we should not simply divide both sides by sin(x) to acquire 2sin(x) = 1. The problem with the operation is that we are dividing by sin(x), yet we do not know what the value of x is. Thus, one or more values of x may result in sin(x) = 0, and we cannot divide by 0. Hence, we are required to subtract and then factor, unless the question specifically states that sin(x) ≠ 0.

Which is a number that can be written as a fraction in the form ?

Answers

Rational Numbers: Any number that can be written in fraction form is a rational number. This includes integers, terminating decimals, and repeating decimals as well as fractions. An integer can be written as a fraction simply by giving it a denominator of one, so any integer is a rational number.

Hope this helps!

The sophomore class needs a combined total of 216 medium and large t-shirts for field day. The number of medium t-shirts needed is three times the number of large t-shirts needed. Based on this information, would it be reasonable for the sophomore class to order 72 large t-shirts and 144 medium t-shirts? A. No, because the number of medium t-shirts is not 3 times the number of large t-shirts B. No, because the number of large t-shirts is not 3 times the number of medium t-shirts C. Yes, because the total number of t-shirts is 216 D. Yes, because the number of large t-shirts is of the total number of t-shirts​

Answers

It could be c as your answer

Find m A) 70°
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B) 145°
D) 130°

Answers

Answer:

42 degrees

Step-by-step explanation:

Angles E and G are equal.  Therefore, 8x - 6 = 7x, and x = 6.

Then the measure of angle G must be 7(6), or 42 degrees.

Use the distance formula to find the distance between each pair of points. round to the nearest tenth of neccessary.

Answers

Answer:

1). 4.2    2). 7.65    3). 14.14

Step-by-step explanation:

1). √(y2 - y1)² + (x2 - x1)²

√[-1 - (-4)]² + [-3 - (-6)]²

√(3)² + (3)²

√9 + 9

√18

= 4.2

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√(1.5)² + (-7.5)²

√(2.25) + (56.25)

√58.5

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Answers

A=b h................

Answer:

A = 20

Step-by-step explanation:

A = bh

b = 4

h = 5

4 × 5 = 20


Reese is selling lemonade at the parade. He gets to keep 50% of the money he collects. A large lemonade is
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.0.50(5l + 2s)

Use the Distributive Property to expand the expression.

Answers

Answer:

.5(5I)+.5(2s)

Step-by-step explanation:

What is the value of x?

Answers

Answer:

x = 64

Step-by-step explanation:

2x = 128

x = 64

Answer:

hi

Step-by-step explanation:

i think so

128⁰+2x⁰=180⁰

2x⁰=180⁰-128⁰

2x⁰=52⁰

x=52/2

x=26⁰

hope it helps

have a nice day

CHOOSING BRAINLIEST ( SCREENSHOT PROVIDED )

Find the missing number to complete the linear equation that gives the rule for this table.


x | y

0 | 0

1 | 25

2 | 50

3 | 75

Answers

Answer:

y= 25

i think

Step-by-step explanation:

Which of these is an example of due process?

a search without good reason

a prejudiced jury

a cruel punishment

a fair trial

Answers

Answer:

A fair trial.

Answer:

Step-by-step explanation: a search without good reason

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If Peter rents a car and pays a cost of $85, how many hours did he rent it for?

Answers

he would have rented the car for 7 hours

Jen collects stamps. The first month she added 25 stamps. Six months later, she doubled in number to a total of 98. How many stamps did she have to start her collection?

Answers

Answer:

49

Step-by-step explanation:

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Answers

If you mea. 1 . -28 - 20 then the answer is going to be

[tex]1. - 48[/tex]

but if you mean -28 -20 the the answer is going to be

[tex] - 48[/tex]

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Answers

Answer:

∠ U = 60°

Step-by-step explanation:

The tangent- tangent angle U is half the difference of its intercepted arcs

minor arc VT = 120° , then

major arc VT = 360° - 120° = 240°

Then

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PLZ HELP NEED BY TODAY!!

Answers

Step-by-step explanation:

Given 5x + 8 = 118 (vertically opposite angles)

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Answers

Answer:

12

Step-by-step explanation:

5^2 + x^2 = 13^2

x = 12

Answer:

12

Step-by-step explanation:

Use Pythagorean theorem

[tex]a^2 +b^2 =c^2[/tex]

c= always hypotenuse/ longest side/ side across from right angle = 13

a= 5

[tex]5^2+b^2=13^2[/tex]

[tex]25+b^2=169[/tex]

Subtract 25 from 169

[tex]b^2= 144[/tex]

Square root both sides

b= 12

--------

it's also a special triangle known as a 5, 12, 13 triangle

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Answers

Answer:

45%

Step-by-step explanation:

Solve for x. round your answer to the nearest tenth
Trigonometry ​

Answers

Answer:

[tex]\displaystyle x \approx 16.5[/tex]

General Formulas and Concepts:

Pre-Algebra

Order of Operations: BPEMDAS

Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to Right  

Equality Properties

Multiplication Property of Equality Division Property of Equality Addition Property of Equality Subtraction Property of Equality

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[Right Triangles Only] SOHCAHTOA[Right Triangles Only] tanθ = opposite over adjacent

Step-by-step explanation:

Step 1: Define

Angle θ = 70°

Opposite Leg = x

Adjacent Leg = 6

Step 2: Solve for x

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For every 2 cups of lemonade, there are 3 cups of iced tea.
For every 2 cups of lemonade, there are 5 cups of iced tea.
For every 3 cups of lemonade, there are 2 cups of iced tea.
For every 5 cups of lemonade, there are 2 cups of iced tea.

Answers

Answer:

Answer 2 would be true.

Step-by-step explanation:

Because our ratio is 2:5 (or 2 to 5 for easier understanding) we know that every 2 cups we use of lemonade, we pair with 5 cups of tea.

Answer:

The answer is B

Step-by-step explanation:

For every 2 cups of lemonade, there are 5 cups of iced tea.

Please help have only an hour please use picture

Answers

Answer:

The answer is C. n = 3

Step-by-step explanation:

I got this answer by using the butterfly method. I multiplied 3 and 2 and got 6. Then take 6 and divide it by 2 and you get 3.

So therefore, n = 3

Please mark brainliest if this helped.

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Step-by-step explanation:

First croas multiply the 2 and 3 to get one side

then you multiply 2n and move it to the other side so it can equal

2n=6  

2n/2=6/2

n=3

What is a equivalent expression to z+z+z+z

Answers

Answer: 4z or z * 4 or 4 * z

*all three expressions above are the same and correct pick which ever one you want to use

angle A and angle B are complementary angles. If m angle A = (6x – 8)° and m
angle B = (5x + 21)°, then find the measure of angle B.

Answers

Answer: B = 56 degrees

Step-by-step explanation: Complementary angles add up 90 degrees. So we will set both of the equations equal to 90 degrees and then solve from there.

6x+8+5x+21=90

1. Simplify 5x + 6x and 21 - 8

11x+13=90

 

2. Subtract 13 from both sides.

11x=90-13

 

3. Simplify 90-13 to 77.

11x=77  

4. Divide both sides by 11.

x = 77/11

​    

5. Simplify 77/11 to 7

 x=7

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1. Substitute

B = (5(7)+21)

B = 35 +21

B = 56

HOPE THIS HELPS :)

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Answers

Answer:

8 is the height

Step-by-step explanation:

please mark this answer as brainlest

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Answer:

Thaey are proportional

Step-by-step explanation:

Multiply. Write your answer as a fraction in simplest form.
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asap

Answers

Answer:

-9/20

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Answers

Answer:

1 ounce is 0.05

Step-by-step explanation:


someone please help me

Answers

Answer:

A. 20ft

Step-by-step explanation:

Answer:

d. 98.5

Step-by-step explanation:

Triangles:

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Circle:

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Find x. PQR = MNR ...............

Answers

Answer:

x = 55

Step-by-step explanation:

<QRP = <NRM because of vertical angles

To find <NRM:

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x + 125 = 180

x = 55

<NRM = 55

<QRP or x = 55

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