A racing shell, which is a boat a crew team rows, moves 20 km/h in still water. During practice, the team rows 36 km against the current and 22 km with the current. Find the speed of the river current if the team rows a total of 3 hours.

Answers

Answer 1

Answer:

2 km/h

Step-by-step explanation:

Let x represent the speed of the river current, t₁ be the time spent rowing against the current and t₂ be the time spent rowing with the current.

Since the speed of the still water = 20 km/h.

The speed of rowing against the current = (20 - x)

The speed of rowing with the current = (20 + x)

We know that velocity = distance / time. Hence time = distance / velocity

t₁ = 36 / (20 - x)

t₂ = 22 / (20 + x)

but t₁ + t₂ = 3 hours

Therefore:

3 = 36 / (20 - x) + 22 / (20 + x)

multiply through by 400 - x²

3(400 - x²) = 36(20 + x) + 22(20 - x)

1200 - 3x² = 720 + 36x + 440 - 22x

3x² + 14x -40 = 0

This gives x = -6.7 or x = 2

x cannot be negative therefore x = 2 km/h

The speed of the river current is 2 km/h

Answer 2

Answer:

2km/h is correct

Step-by-step explanation:

The other guy is absolutely correct


Related Questions

3(-4+4)+5n=2n what are the steps for finding n

Answers

Answer:

1. Move the variables to one side: 3(-4+4) = -3n

2. Distribute. You will end up with 0 = -3n

3. Divide both sides by -3. n = 0

Step-by-step explanation:

Answer:

n=0

Step-by-step explanation:

3(-4+4)+5n=2n

first distribute

-12+12+5n=2n

combine like terms

5n=2n

subtract 2n on both sides

3n=0

divide by 3 on both sides

n=0/3

which is also equal to

n=0

The two objects are the same height, and the cylinder is just wide enough for the the box to fit inside with all 4 vertical edges of the box touching the inside of the cylinder. if the box of pasta fits 8 cups of rice, estimate how many cups of rice will fit inside the cylinder. Expalin or show your reasoing

Answers

Answer:

The answer is below

Step-by-step explanation:

The volume of a box with a length of l, width of w and a height of h is given by the formula:

volume of the box = length * width * height = lwh

The volume of a cylinder with a height of h, and radius r is given by the formula:

volume of the cylinder = π * radius² * height = πr²h

Since the box and the cylinder have the same height and the cylinder is wide enough for the box to be placed inside, this means that the box has a volume greater than that of the cylinder. Hence:

If the box can take 8 cups, the cylinder would be able to take 10 cups.

Consider the line x-2y=-1 What is the slope of a line parallel to this line? What is the slope of a line perpendicular to this line?

Answers

Answer:

slope of line that is parallel is 1/2

slope of line that is perpendicular is -2

Step-by-step explanation:

parallel lines have the same slope

perpendicular lines have slopes that are opposite and reciprocal

x - 2y = -1

-2y = -x -1

y = 1/2x + 1/2

the coefficient of the 'x' term represents the slope

Please help! What mistake did I make?

Answers

Answer:

Step-by-step explanation:

to make a negative, in addition, you can’t add a negative with a positive or the number would go from -3 + 2 = -1.

Solve please I don’t know how to do this.

Answers

Answer:

its 63 lol

Step-by-step explanation:

Answer:

63

Step-by-step explanation:

x/3-10=11

x/3=21

crisscross then

x=21×3

c=63

Write an explicit formula for the nth term of this sequence:

6, 11, 16, 21, . . .

1. an=5n+11

2. an=5n+1

3. an=21-5n

4. an=6n+1

Answers

Answer:

2)an = 5n + 1

Step-by-step explanation:

This is an arithmetic series.

6 , 11 , 16, 21 ,.....

First term = [tex]a_{1}[/tex] = 6

Common difference = d = second term - first term

                                = 11 - 6 = 5

nth term = [tex]a_{1}+(n-1)*d[/tex]

             = 6 + (n - 1) * 5

            =  6 + n * 5 - 1*5

            = 6 +5n - 5

           = 6 - 5 + 5n

           = 1 + 5n

Ms. Meyer washed
2/7
of her laundry. Her son washed
1/4
of it. Who washed most of the laundry? How much of the laundry still needs to be washed?
Solve this on paper. Then check your work on Zearn.
write your answer as a fraction ill mark you !

Answers

Answer:

15/28 loads of laundry needs to be washed.

Step-by-step explanation:

2/7 + 1/4

=  

2 × 4 + 1 × 7

7 × 4 + 4 × 7

=  

8/28 + 7/28

=  

8 + 7/ 28

=  

15/28

-14 = 4x - 2
what is the x ?

Answers

Answer:

X = -3

Step-by-step explanation:

Which expression is the result of factoring the expression below by taking out its greatest common factor?
8x2 – 24 = ?

Answers

Answer:

Step-by-step explanation:

You need to give us the choices. However, I will try and give you the answer.

The highest common factor is 8

8(x^2 - 3)     This is the answer I think the question expects.

8(x - √3 )(x + √3)  this is also possible

determine the slope and y-intercept from following the equation: y= 3/2x + 3

Answers

Answer:

Slope is 3/2 and y-intercept is +3

Step-by-step explanation:

slope = m

y intercept = b

Slope is 3/2 and y-intercept is +3

Solve the equations 25 - 3x = 40. Write the problem on the sketch pad then solve the problem algebraically. I need the answer and how you work it out :)

Answers

Answer:

Step-by-step explanation:

25-3x=40

25-25-3x=40-25

-3x=15

-3x/-3=15/-3

x=-5

A baseball team had 70 players show up for tryouts last year and this year had 85 players show up for tryouts. Find the percent increase in players from last year to this year.

Answers

Answer:percent increase in players from last year to this year= 7.14%

Step-by-step explanation:

percent increase = (Increase  in number of players /Initial value of players Last year)  x 100

value of players for tryouts  last year = 70

value of players for tryouts this year = 85

Increase in tryouts = 85-70 =5

percent increase = 5/70 x 100

= 7.14%

What’s the answer for this one??

Answers

Answer:

It is the second one.

Step-by-step explanation:

a and e are equal because they are mirrored. d and b are equal because they are on the same  line and at the same point where the parallel lines go through. b and f are also mirrored. That leaves c and e which don't match.

Five less than twice the value of a number is equal to three times the quantity of
four more than one-half the number. What is the
number?
a. Let x be the number. Write and solve an equation to find x. Show your work.
b. Does the solution of your equation solve the original problem? Explain.

Answers

Answer:

a) x = 34

b) yes, it checks out

Step-by-step explanation:

2x - 5 = 3(4 + 1/2x)

multiply both sides by 2 to eliminate fraction

2[2x - 5 = 3(4 + 1/2x)] = 4x - 10 = 24 + 3x

x - 10 = 24

x = 34

check

2(34) - 5 = 3(4 + 34/2)

68 - 5 = 3(4 + 17)

63 = 3(21)

63 = 63

solve for x...................................................................................

Answers

Answer:

x = 36°

Step-by-step explanation:

x + 20° + 4x = 200° { exterior angle of a triangle is equal to the sum of two opposite interior angles }

5x = 200° - 20°

5x = 180°

x = 180° / 5

x = 36°

Hope it will help :)

40 points and brainliest! Please explain your answer!!!

Answers

Answer:

give the other person brainliest

Step-by-step explanation:

the answer is B. 62°

the correct answer to the question is the answer is B. 62°

$325 is borrowed from a bank that charges 4% interest compounded annually. How much is owed after 1 year, 3
years, 7 years, and 20 years?

Answers

Answer:

338

365.58

427.68

712.12

Step-by-step explanation:

for annually compounding interest

PV(1+i)^n

for one year

325(1.04)

338

for 3 years

325(1.04)^3

365.58

For 7 years

325(1.04)^7

427.68

for 20 years

325(1.04)^20

712.12


What is the value of -2(x + 5)?​

Answers

Answer:

-2x-10

Step-by-step explanation:

hope it hhhhheeeeeellllpppp you

What is 5 / 1? Explain.

(Just trying to give away easy points haha)

Answers

Answer:

5/1 = 5

Step-by-step explanation:

because 5/1 equals 5.

Find the upper bound

Answers

The upper bound is 56cm I think

Triangle ABC is rotated counterclockwise using the origin as the center of rotation. The preimage and image are shown in the graph below. On a coordinate plane, triangle A B C has points (negative 4, negative 2), (negative 2, 1), (negative 2, negative 1). Triangle A prime B prime C prime has points (1.2, 4.2), (2, 1), (0, 2.9). Which rotation could have taken place?

Answers

Answer: it would be C. a 225° rotation

Step-by-step explanation: I got it correct

Answer:

C

Step-by-step explanation:

If cos θ > 0, which quadrant(s) could the terminal side of θ lie?

Answers

Answer:

I and IV

Step-by-step explanation:

cosine is positive/greater than 0 in quadrants I and IV. Its just a rule of the unit circle.

Can remember by All Star Trig Class

meaning all the trig funtions are positive in quadrant I

sin is positive in II

tan is positive in III

and cos is positive in IV

30+5z+5z=180
what is the value of z

Answers

Answer:

15

.......................

the value of z is 15

Hits 2) How many solutions does the inequality have?
A) 0
B) 1
C) 8
D) infinitely many​

Answers

9514 1404 393

Answer:

  D)  infinitely many

Step-by-step explanation:

There are infinitely many points on any portion of the number line. The shading on the graph indicates all numbers less than or equal to 8 are solutions. There are infinitely many such numbers.

A 34 foot flag pole is casting a shadow that is 17 feet long. How far is the top of the flag pole from the the end of the shadow?

Answers

Answer:

17*square root of 5

Step-by-step explanation:

Form a triangle like the one shown  below and use the pythagorean theorem:

[tex]17^2+34^2=c^2\\289+1156=c^2\\1445 = c^2\\c = \sqrt{1445} \\c = 17\sqrt{5}[/tex]

Find the area of the trapezoid 12.5cm 6cm 17.5cm

Answers

Answer:

The answer for this is a. 90

need help with all 3 pleaseeee

Answers

A.
A.
D.
Hope this helps!!
A
A
D
Hope this helps!!

Please help! Will mark brainliest if correct! Use the model attached to answer

Answers

Answer:

4 cubes will be shown in the right view of the model and the 1st option is the top view for the model.

A and b I think I hope

-30÷5=
bunun cevabı 6 mı??​

Answers

Answer:

-6

Step-by-step explanation:

-30÷5=-6

this is the ans

Which type of transformation is described by (x, y) (x + 2, Y-3)?

Answers

Answer:

I’m good at math but not that good

Step-by-step explanation:

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