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
mamaluj [8]
3 years ago
5

Two cars left the city for a suburb, 480 km away, at the same time. The speed of one of the cars was 20 km/hour greater than the

speed of the other, and that is why it arrived at the suburb 2 hour earlier than the other car. Find the speeds of both cars.
Mathematics
1 answer:
Alex_Xolod [135]3 years ago
4 0

The speed of both the cars are 80km/h and 60km/h

<u>Step-by-step explanation:</u>

Let the speed of one car be 'a' and the speed of other car be 'b'.

The total distance (d) = 480km

It is given that the speed of one car is 20km/h faster than the other.

 We can write,

       a = b+20

The slower car takes 2 hrs more to reach the suburb than the other car.

Let the time taken by the fastest car be t

Speed = distance/time

So,

a = 480/ t

b = 480/(t+2)

We got the values of a and b.

a = b+20

480/t = (480/(t+2))  + 20

Taking LCM on the right side.

480/t = (480 + 20t + 40) / (t+2)

480(t+2) = (480+20t+40) t

480t + 960 = 480t + 20t(t) + 40t

20t(t) + 40t - 960 = 0

Divide the whole equation by 20 to simplify the equation.

t(t) + 2t - 48 = 0

Solve the quadratic equation by splitting the middle terms.

t(t) + 8t - 6t - 48 = 0

t(t + 8) - 6(t + 8) = 0

(t- 6) (t+8) =0

t = 6 (or) -8

t is time and cannot be negative. So t= 6hrs

a = 480/t

a = 480/ 6 = 80

the speed of the fastest car is 80km/hr

a = b + 20

b = a - 20

b = 80 - 20

b = 60km/h

You might be interested in
How do I draw and determine the equation of a trend line on a scatterplot
Nat2105 [25]

Step-by-step explanation:

Step 1: Draw your trend line.

You begin by drawing your trend line. You want your trend line to follow your data. You want to have roughly half your data above the line and the other half below the line, like this:

trend line equation

Step 2: Locate two points on the line.

Your next step is to locate two points on the trend line. Look carefully at your trend line and look for two easy to figure out points on the line. Ideally, these are points where the trend line crosses a clearly identifiable location.

For the trend line that we just drew, we can see these two easily identifiable points.

trend line equation

We can easily identify these two points as (3, 3) and (12, 6).

Step 3: Plug these two points into the formula for slope.

The formula for slope is this one:

trend line equation

We can label our first point as (x1,y1), and our second point as (x2,y2). So our x1 is 3, our y1 is 3, our x2 is 12, and our y2 is 6. Plugging these values into the equation for slope and evaluating, we get this:

trend line equation

So our slope is 1/3.

8 0
3 years ago
I conclude from the information given that he is just very lucky. I believe he is lucky, because it is very hard to perform tric
VikaD [51]

Answer:

I believe that the owner of the dice is actually not lucky. There are people who practice throwing dice in a controlled way in order to get a specific side of the dice. If he practices his dice throwing a lot, then he would have a much higher chance of winning at a game of dice.

Step-by-step explanation:

Since you said he was lucky, I decided to make an answer saying that he wasn't lucky so you can choose between both of them. Your answer was good as well.

7 0
3 years ago
Which statement about these rectangles is true? 4(1.5) 4 2(1.5) Image 2(1.5) Pre-Image 2 4(1.5)​
Anna007 [38]

Answer:

it is a because I said it is a

4 0
3 years ago
4.
Sloan [31]

Answer:

she

Step-by-step explanation:

bc c

3 0
3 years ago
Read 2 more answers
How many solutions does the system have? Y=-2x-4 y=3x+3
Fudgin [204]

Answer:

1

Step-by-step explanation:

Since they are not parallel nor the same line, they have 1 intersecting point, which is the solution.

If they were parallel, they would have no solution.

If they were the same line, they would have infinite solutions.

5 0
4 years ago
Other questions:
  • Can somebody give me some problems involving residuals?
    9·1 answer
  • It says 6+10 ÷2 -1*4
    10·1 answer
  • Shorts are on sale for 10% off. If Kate buys 10 pairs of shorts at s dollars apiece, which expression is NOT equivalent to the s
    8·2 answers
  • 3 ordered pairs that satisfy the equation y=12x
    9·2 answers
  • A circle has a circumference of 7850 units. What is the radius?
    7·1 answer
  • Cross sections are formed by slicing through figure parallel to its base. in which figure will the cross section and the base NO
    10·2 answers
  • Write your answer in simplest form. 11 2/16 - 8 3/16
    6·1 answer
  • The width of a rectangle measures (3v-3w) centimeters, and its length measures (5v-9w) centimeters. Which expression represents
    7·1 answer
  • How do i do this, my son is struggling and he needs help
    9·2 answers
  • Using everyday knowledge, indicate whether the if then statements are correct forward-only or both forward and reverse. Statemen
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!