1answer.
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
soldi70 [24.7K]
3 years ago
11

A motorboat covers the distance from one pier to the other pier in 4 hours and the way back in 5 hours. What is the speed of the

boat in still water, if it covers 70 km with the current in 3.5 hours?
(its not 20 i tried)
Mathematics
1 answer:
aleksklad [387]3 years ago
3 0
R = speed in still water
r + c = speed with current
r - c = speed against current

3.5(r + c) = 70
r + c = 20
c = 20 - r

4(r + c) = distance from pier to pier
5(r - c) = distance from pier to pier
4(r + c) = 5(r - c)
4(r + 20 - r) = 5(r - 20 + r)
80 = 10r - 100
180 = 10r
18 = r
The speed in still water is 18 km/hour
You might be interested in
Pls and thanks help me
PIT_PIT [208]
She spent 200 minutes
6 0
3 years ago
How can I make these a single fraction?
Serga [27]

in the like term you can add directly and make it single fraction and in unlike term you have to take LCM of denominator .

6 0
3 years ago
The first three steps in determining the solution set of the system of equations algebraically are shown in the table. y = −x2 +
lianna [129]
You have a system of equations \left \{ {{y = -x^2+2x-9} \atop {y =-6x+6}} \right..

1. Substitude right side of second equation into the left side of the first equation: -6x+6=-x^2+2x-9.

2. Solve this equation:
 x^2-2x+9-6x+6=0, \\ x^2-8x+15=0, \\ D=(-8)^2-4\cdot 1\cdot 15=64-60=4,  \\ \sqrt{D}=2,  \\ x_{1,2}=\dfrac{8\pm 2}{2  } =3,5.

3. Find y:
for x_1=3, y_1=-6\cdot 3+6=-18+6=-12,
for x_2=5, y_2=-6\cdot 5+6=-30+6=-24.

4. The solutions of the system are: (3,-12) and (5,-24).
Answer: Correct choice is A.


7 0
3 years ago
Read 2 more answers
From his eye, which stands 1.59 meters above the ground, Francisco measures the
viva [34]

The height of the skyscraper to the nearest tenth is 234. 95 meters.

<h3>How to determine the height</h3>

From the information given, we have:

  • angle of elevation = 32°
  • length of the base, adjacent side = 376 meters
  • height of the skyscraper, opposite side = x meters

To determine the height of the elevator, let's use the tangent identity

We have that;

tan θ = opposite/ adjacent

The value of the opposite side is 'x' which is the height of the skyscraper and the value of the adjacent side is 376 meters which is the length of the base of the skyscraper

Now, substitute the values, we have;

tan 32 = x/ 376

cross multiply

x = tan 32 × 376

x = 0. 6249 × 376

x = 234. 95 meters

We know that the 'x' represents the opposite side and thus the height of the skyscraper

Thus, the height of the skyscraper to the nearest tenth is 234. 95 meters.

Learn more about angle of elevation here:

brainly.com/question/19594654

#SPJ1

7 0
2 years ago
True or False: A square is a specific type of parallelogram?
sergejj [24]
False, they are both quadrilaterals though.
6 0
3 years ago
Read 2 more answers
Other questions:
  • Marco sorted these solid figures into two groups. What is true about the groups?
    12·1 answer
  • The quadratic function
    11·1 answer
  • What is Y minus negative 5
    14·2 answers
  • Numbers 1 - 10 are written on cards and placed in a bag. Find the probability of choosing a number greater than 5 or choosing an
    7·1 answer
  • Is 6/3 equal to 2 whole?
    9·2 answers
  • What is the equation of a line that passes through the point -(6,6) and has a slope of 1/3​
    14·1 answer
  • The price of a community pool membership has a one-time sign-up fee and a monthly fee. The price can be modeled by the function
    12·1 answer
  • Find the length of GH.
    12·2 answers
  • What is the measure of arc WYZ?
    10·2 answers
  • Assume that X is Normal with mean $ 240 and standard deviation $60 . the probability that , in a randomly selected week , Dan wi
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!