Rosea drives her car 30 kilometers to the train
station, where she boards a train to complete her trip. The
total trip is 120 kilometers. The average speed of the train is
20 kilometers per hour faster than that of the car. At what speed
must she drive her car if the total time for the trip is less than
2.5 hours?

Answers

Answer 1

Answer:

>34.88km/h

Step-by-step explanation:

Because we have two unknown values in this question (speed of train and speed of car), we will need two equations to solve it.

Firstly, we can make a big equation for time in terms of the vehicle speeds. Time = distance / speed, so if we use t for the train speed and c for the car speed, we get this equation for speed:

30/c + 90/t = 2.5

Here the 30 is the distance traveled by the car in km and the 90 is the distance traveled by the train in km (120 - 30 = 90).

We also know that the train speed was 20km/h faster than the car speed so our second equation is:

c + 20 = t

So now we can substitute this in the big equation so we only have one variable to solve for:

30/c + 90/(c+20) = 2.5

Now to solve this, this first step is to get rid of the fractions, which we can do by multiplying all the terms by the lowest common factor of the two denominators which is c(c+20):

(30/c)*c(c+20) + (90/c+20)*c(c+20) = 2.5

This simplifies to:

120c+600=2.5c^2+50c

and then into the quadratic equation:

2.5c^2-70c-600=0

This can be solved with the quadratic formula or a solver/calculator, and yields the solutions:

c=−6.88, 34.88 (both to 2dp)

We can eliminate the negative solution because speed cannot be negative meaning that Rosea must drive her car at the speed of at least/greater than 34.88km/h if she wants the total trip to be less than 2.5 hours.

Hope this helped!


Related Questions

-0.56x+0.26x=6’6
?x=6.6
X=6.6
___

X=??

Answers

-0.56+0.26
-0.3x=6.6
X=6.6/-0.3
X=6.3

Answer:

x = -22

Step-by-step explanation:

Solving in steps:

-0.56x+0.26x=6.6-0.3x = 6.6x = 6.6/(-0.3)x = -22

What type of number is -1/3

Answers

Answer:

a rational number

Step-by-step explanation:

Rational number are numbers that can be written as a fraction where both the numerator and denominator are integers. This means that both the top and bottom of the fraction are whole numbers.

help me please!!!!!!!​

Answers

Answer:

A'(-5, 6)B'(-5, 2)C'(-9, 2)D'(-9, 6)

Step-by-step explanation:

Rotation 180° about the origin changes the sign of every coordinate. The image coordinates are shown above.

Tyrone makes a scale drawing of his backyard. The scale from the
backyard to the drawing is 2 ft to 1 in. The width of the patio on the
drawing is 8 in. What is the width of Tyrone's actual patio? Write your
answer as a ratio (FOR EXAMPLE 2:1) NO LETTERS

Answers

Answer:

16:8 is the width of the patio

Jennifer is saving money to buy a bike. The bike costs $294. She has $126 saved, and each week she adds
$14 to her savings.
How long will it take her to save enough money to buy the bike?
It will take her
weeks to save for the bike.

Answers

Answer:

the answer should be 12 weeks

Step-by-step explanation:

Because, 294-126=168 and 168 divided by 14 is 12

HELPP MEEE IO PRAY THE LORD FOR SOMEONE TO HELPP

Answers

answer 3(n+4)=(n/2)-8

Step-by-step explanation:

...idk hope this one helps

HELP SOS!!!!!!!!!!!!!!!!!!!!!!!

Answers

63.83% of them have cars

9 x 10' =
______________________

Answers

Answer:

9 x 10 = 90

Step-by-step explanation:

Answer:

90

Step-by-step explanation:

9x1=9 then add the zero

=90

Solve for n.
n + 1 = 4(6-8)

A.n=1
B.n=8
C.n=11
D.n=16

Answers

Simplify 6 - 8 to -2

n + 1 = 4 * -2

Simplify 4 * - 2 to -8

n + 1 = -8

Subtract 1 from both sides

n = -8 - 1

Simplify -8 - 1 to -9

n = -9

Check answer:

n + 1 = 4(6 - 8)

Let n = -9

-9 + 1 = 4 * (6 - 8)

Simplify 6 - 8 to -2

-9 + 1 = 4 * -2

Simplify 4 * -2 to -8

-9 + 1 = 8

n = 8

Answer:

n=9

Step-by-step explanation:

n+1=4(6-8)

We move all terms to the left:

n+1-(4(6-8))=0

We add all the numbers together, and all the variables

n+1-(4(-2))=0

We add all the numbers together, and all the variables

n+9=0

We move all terms containing n to the left, all other terms to the right

n=9

The answer should be n=9

8. Fill in the blank. The ___
form of the equation of a line with a slope
m passing through (x1y1) is y- y1= m(x-x1).

Answers

is it point slope form

Find the distance between each pair of points (8,5) ,(-1,3)

Answers

Answer:

d=9.220

Step-by-step explanation:

Answer:

sqrt(85)

Step-by-step explanation:

Use the distance formula.

d = sqrt[(x2 - x1)^2 + (y2 - y1)^2]

d = sqrt[(-1 - 8)^2 + (3 - 5)^2]

d = sqrt[(-9)^2 + (-2)^2]

d = sqrt[81 + 4]

d = sqrt(85)

Answer: sqrt(85)

Someone plzz answer only number 9 easy!!
(Correct will mark as brainliest)
Thanks guys

Answers

Answer:

4×102 +5×101 +6×100 +8 × 10-1 +1 × 10-2

I hope that made sense lol

Answer:

400 + 50 + 6 + 0.8 + 0.01

Step-by-step explanation:

This is the answer because:

1) Expanded form means to write a number with its full value. It is shown as a sum of each digit multiplied by its matching place value

2) Therefore, the answer is 400 + 50 + 6 + 0.8 + 0.01

Hope this helps!

Help me please this is due in 10 minutes, please help !!!

Answers

Answer:

Step-by-step explanation:

the answer is d

i beg someone to answer ive posted this 3 times and im still not sure how to do it.....

Which of the following is the best estimate for the number of seconds which have elapsed since the start of the year 2000?

(note: date was June 2001)

A) 3 X 10⁴
B) 3 x 10⁵
C) 3 x 10⁶
D) 3 X 10⁷
E) 3 X 10⁸​​

(with working out please​)

Answers

Answer:

D) 3 X 10⁷

Step-by-step explanation:

Estimated days:

Jan 2000 to June 2001 = 1.5 years = 365*1.5 days ≈ 548 days

1 day = 24 hours = 24*60 minutes = 24*60*60 seconds = 86400 seconds

548 days = 548 * 86400 seconds = 47347200 ≈ 4.7*10⁷

Best estimate is D) 3 X 10⁷

Is it B or C? I forgot for when you simplify if you either multiply or add.

Answers

Answer:

B

Step-by-step explanation:

[tex](w^8)^8=w^{8\times8}=w^{64}[/tex]

But,

[tex]w^8\times w^8=w^{8+8}=w^{16}[/tex]

Write 0.2 repeating as a fraction in simplest form.

Answers

Answer:

[tex]\frac{2}{9}[/tex]

Step-by-step explanation:

We require to create 2 fractions with the repeating 2 after the decimal point.

let x = 0.22.... → (1) ← multiply both sides by 10

10x = 2.22....... → (2)

Subtract (1) from (2) thus eliminating the repeating decimal

9x = 2 ( divide both sides by 9 )

x = [tex]\frac{2}{9}[/tex]

Thus

0.22..... = [tex]\frac{2}{9}[/tex]

Answer:

2/9

Step-by-step explanation:

We require to create 2 fractions with the repeating 2 after the decimal point.

let x = 0.22.... → (1) ← multiply both sides by 10

10x = 2.22....... → (2)

Subtract (1) from (2) thus eliminating the repeating decimal

9x = 2 ( divide both sides by 9 )

x =

Thus

0.22..... =

Juan is rappelling down a 495-foot cliff at a rate of 6 feet per second. Which equation would represent the height Juan is above the ground, H, after t seconds?

Answers

Answer:

The equation is H = 495 -6t

Step-by-step explanation:

Here, we want to write an equation that will represent the height Juan is above the ground, after t seconds.

The height we want to calculate is H. The initial height is 495 foot;

At the first second, the decrease in height will be 6 * 1, at the second 6 * 2 and thus at t seconds, the decrease in height will be 6 * t = 6t

Ask the height after t seconds will be;

H = 495 - 6t

Where t represents the time in seconds

combining like terms with negative coefficients
2x-4xy+5x-2xy-4x-4y?

Answers

67885 truing 6788 yea that ab it

Answer: 3x-6xy-4y

Step-by-step explanation: So, it’s been a few years since I’ve been in high school, but if I remember correctly...it should break down as such...

A good method to breaking this down is to use parentheses to break up the equation.

Example: (2x)(-4xy)(+5x)(-2xy)(-4x)(-4y)

Keep in mind we are only using the parentheses as a breaker and not as multiplication as it can be seen.

So, start with the singular ‘x’ variants. (2x) (+5x) (-4x). 2x+5x is 7x. 7x-4x is 3x. Now, move onto ‘xy’ variant. (-4xy) and (-2xy). As these are both negative, they add together to make an even lower number...being -6xy. Onto the final step taking the singular ‘y’ variant. There’s only 1 ‘y’ variant so it just stays -4y.

In the end, you end up with 3x-6xy-4y. :) Hope this helps. If you have any more questions, let me know!

25 more than 8 times a number is the same as 50 less than the product of -5 and the number.

Answers

Answer:

-5x-50=8x+25 solve that

13x= -75

-5.769

Step-by-step explanation:

A football team is selling coupon books for $20 each to raise money. The team wants to
raise at least $1500. The team has already sold 45 coupon books. How many additional
ers.
books does the team need to sell to meet its goal?

Answers

Answer:

jumanah75 the answer is 30 more coupon books.

Step-by-step explanation:

20*45 = 900. Need $600 more20* __ = 600600/20 = 30900+600 = 1500. So therfore, the team needs to sell 30 more books :)

which shows the image of rectangle ABCD after rotation (x,y) (-y,x)​

Answers

Answer:

The first one

Step-by-step explanation:

the C y value is 4 and the first one's C' x value is -4

proving x=>-y

Answer: The correct answer is A

Step-by-step explanation:

Defined as a set of all points equidistant from a given point.
A)
arc
B)
angle
C)
circle
D)
line segment

Answers

Answer:

C

The answer is C and the distant from a given point to a point on the Circle is radius

A. 67
B. 47
C. 52
D. 26

Answers

Answer:

Step-by-step explanation:

22 - 55 + 4x = 2x + 7

4x - 33 = 2x + 7

2x - 33 = 7

2x = 40

x= 20

22 - 55 + 4(20) = 2(20) + 7

80 - 33   = 40 + 7

  47 = 47

answer is B

Answer:

The answer is B

Step-by-step explanation:

Enter the decimal value positioned at point B.

Answers

Answer:

-2.25

Step-by-step explanation:

each mark represents 0.25

Decimal value positioned at point B is -2.25

What is Number system?

A number system is defined as a system of writing to express numbers.

A number line can be defined as a pictorial representation of numbers on a straight line.

In the given number line each line represents 0.25 (zero point two five value).

As B is in between -2 and -3.

So B value is between minus two and minus three

The values which can be between -2 and -3 are -2.25, -2.5, -2.75.

The decimal value positioned at point B is -2.25

Hence decimal value positioned at point B is -2.25

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f(x) = x^2-3x + 7. find f(-1)

Answers

Answer:

f(x)= x^2-3x+7

(-1)^2-3(-1)+7

1+3+7

11

Step-by-step explanation:

A middle school took all of its 6th grade students on a field trip to see a play at a theatre that has 2000 seats. The students filled 65% of the seats in the theatre. How many 6th graders went on the trip?

Answers

the correct answer is 1300

Jack works at a sporting goods store and makes a commission of 20 percent. His sales for each week are shown below. How much did Jack make in total in commission during all four weeks?

Week
Sales
1
$3,000
2
$2,500
3
$3,500
4
$4,000


$200.00
$260.00
$2,000.00
$2,600.00

Answers

Answer: The answer is D 2,6000.00

Answer:

D

Step-by-step explanation:

Given the original statement "If a number is negative, the additive inverse is positive,” which are true? Select three options. If p = a number is negative and q = the additive inverse is positive, the original statement is p → q. If p = a number is negative and q = the additive inverse is positive, the inverse of the original statement is ~p → ~q. If p = a number is negative and q = the additive inverse is positive, the converse of the original statement is ~q → ~p. If q = a number is negative and p = the additive inverse is positive, the contrapositive of the original statement is ~p → ~q. If q = a number is negative and p = the additive inverse is positive, the converse of the original statement is q → p.

Answers

Answer:

The three options are;

1) If p = a number is negative and q = the additive inverse is positive, the original statement is p → q

2) If p = a number is negative and q = the additive inverse is positive, the original statement the inverse of the original statement is ~p → ~q

3) If q = a number is negative and p = the additive inverse is positive, the contrapositive of the original statement is ~p → ~q

Step-by-step explanation:

Given a statement if p then q, we have, p → q. The converse of the original statement is then, if q, then p while the inverse of the original statement is then if not p then not q, and the contrapositive statement is then if not q then not p

Mathematically, we have;

The given conditional statement;

If a number is negative, the additive inverse is positive which can be expressed as follows;

The conditional statement is p → q

The converse statement is q → p

The inverse statement is ~p → ~q

The contrapositive statement is ~q → ~p

Therefore, we have;

1) The conditional statement, if p = a number is negative and q = the additive inverse is positive, the original statement which is a conditional statement is therefore p → q

2) If p = a number is negative and q = the additive inverse is positive, the original statement, which is a conditional statement is p → q, the inverse of the original conditional statement is therefore, ~p → ~q

3) If q = a number is negative and p = the additive inverse is positive, the original statement, which is a conditional statement is therefore, q → p, the contrapositive of the original conditional statement  is therefore ~p → ~q.

The three options are;

1) If p = a number is negative and q = the additive inverse is positive, the original statement is p → q

2) If p = a number is negative and q = the additive inverse is positive, the original statement the inverse of the original statement is ~p → ~q

3) If q = a number is negative and p = the additive inverse is positive, the contrapositive of the original statement is ~p → ~q

What is additive inverse?

The additive inverse of any number is defined as when it is added to the number it gives zero as a result.

Given a statement if p then q, we have, p → q. The converse of the original statement is then, if q, then p while the inverse of the original statement is then if not p then not q, and the contrapositive statement is then if not q then not p

Mathematically, we have;

The given conditional statement;

If a number is negative, the additive inverse is positive which can be expressed as follows;

The conditional statement is p → q

The converse statement is q → p

The inverse statement is ~p → ~q

The contrapositive statement is ~q → ~p

Therefore, we have;

1) In The conditional statement, if p = a number is negative and q = the additive inverse is positive, the original statement which is a conditional statement is, therefore, p → q

2) If p = a number is negative and q = the additive inverse is positive, the original statement, which is a conditional statement is p → q, the inverse of the original conditional statement is, therefore, ~p → ~q

3) If q = a number is negative and p = the additive inverse is positive, the original statement, which is a conditional statement is, therefore, q → p, the contrapositive of the original conditional statement is, therefore, ~p → ~q

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Which equation describes a line of symmetry for the figure shown? x = 0 y=−x y = x y = 0

Answers

Answer:

y=0

Step-by-step explanation:

Hope this helped!!!

PLEASE HELP FAST! 50 POINTS!
A three digit number when divided by 5 has an even quotient. When it is divided by 3, it also has an even quotient.

A, What is the digit in the one's place?
B, What can the number be?

Answers

Answer:

A. 0

B. there are many options for this but just some examples are

120, 150, 180, 210, 240, 270, 300, 330, 360, 390

Step-by-step explanation:

the rest of the options are

420, 450, 480, 510, 540, 570, 600, 630, 660, 690,

720, 750, 780, 810, 840, 870, 900, 930, 960, 990.

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