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
Leni [432]
3 years ago
8

The average speed of an express train is 15 mi/h faster than the average speed of a local train 2 hours longer than the express

train to cover 360 miles. what is the average speed of the express train?
PLEASE HELP!!!!
Mathematics
1 answer:
natta225 [31]3 years ago
5 0
360÷15×2=48hrs of the express train.
You might be interested in
The fish population in a certain lake rises and falls according to the formula F = 3000(23 + 11t − t2). Here F is the number of
Gemiola [76]

Answer:

a) On January 1, 2017 the fish population will be the same as the initial population.

b) On September 18th, 2018 the fish population will be zero.

Step-by-step explanation:

Hi there!

a) First, let´s write the function:

F(t) = 3000(23 + 11t − t²)

The population on January 1, 2006 is the population at t = 0. Then:

F(0) = 3000(23 + 11· 0 - 0²)

F(0) = 3000 · 23 = 69000

This will be the population every time at which t² - 11t = 0. Then let´s find the other value of t (besides t = 0) that makes that expression to be zero:

t² - 11t = 0

t(t - 11) = 0

t = 0

and

t - 11 = 0

t = 11

On January 1, 2017 (2006 + 11), the fish population will be the same as the initial population.

b) We have to obtain the value of t at which F(t) = 0

F(t) = 3000(23 + 11t − t²)

0 = 3000(23 + 11t − t²)

divide both sides of the equation by 3000

0 = 23 + 11t − t²

Let´s solve this quadratic equation using the quadratic formula:

a = -1

b = 11

c = 23

x = [-b ± √(b² - 4ac)] / 2a

x = 12.8  ( the other value of x is negative and therefore discarded).

After 12.8 years all the fish in the lake will have died.

If 1 year is 12 months, 0.8 years will be:

0.8 years · 12 months/year = 9.6 months

If 1 month is 30 days, 0.6 month will be:

0.6 month · 30 days / month = 18 days

All the fish will have died after 12 years, 9 months and 18 days from January 1, 2006. That is, on September 18th, 2018.

7 0
3 years ago
What is number 61 and a step by step explaination please?
astra-53 [7]

1/3 ln(<em>x</em>) + ln(2) - ln(3) = 3

Recall that m\log_b(n)=\log_b(n^m), so

ln(<em>x</em> ¹ʹ³) + ln(2) - ln(3) = 3

Condense the left side by using sum and difference properties of logarithms:

\log_b(m)+\log_b(n)=\log_b(mn)

\log_b(m)-\log_b(n)=\log_b\left(\dfrac mn\right)

Then

ln(2/3 <em>x</em> ¹ʹ³) = 3

Take the exponential of both sides; that is, write both sides as powers of the constant <em>e</em>. (I'm using exp(<em>x</em>) = <em>e</em> ˣ so I can write it all in one line.)

exp(ln(2/3 <em>x</em> ¹ʹ³)) = exp(3)

Now exp(ln(<em>x</em>)) = <em>x </em>for all <em>x</em>, so this simplifies to

2/3 <em>x</em> ¹ʹ³ = exp(3)

Now solve for <em>x</em>. Multiply both sides by 3/2 :

3/2 × 2/3 <em>x</em> ¹ʹ³ = 3/2 exp(3)

<em>x</em> ¹ʹ³ = 3/2 exp(3)

Raise both sides to the power of 3:

(<em>x</em> ¹ʹ³)³ = (3/2 exp(3))³

<em>x</em> = 3³/2³ exp(3×3)

<em>x</em> = 27/8 exp(9)

which is the same as

<em>x</em> = 27/8 <em>e</em> ⁹

3 0
3 years ago
Amy has 12 brown golf tees, 8 white golf tees, 10 red golf tees, 6 blue golf tees, and 12 green golf tees in her golf bag. If sh
Aleonysh [2.5K]

Answer:

The green tee because i.t is the second largest then the blue or brown even though it is greater then the brown

Step-by-step explanation:

  1. <u>Use mental math and common sense.</u>
6 0
3 years ago
Rewrite the equation 2y+3x=4 in slope-intercept form. then find the slope and y-intercept
Zinaida [17]

Answer:

y=  -3/2-2

Step-by-step explanation:

7 0
3 years ago
HELP MEEEEEEEEEEEEEEEEEEEEE PLEASE!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!HELP MEEEEEEEEEEEEEEEEEEEEE PLEASE!!!!!!!!!!!!!!!!!!!!!!!!!!!
max2010maxim [7]

Answer: 7.9

Step-by-step explanation:

P=2000, r=0.09, n=2\\\\4000=2000\left(1+\frac{0.09}{2} \right)^{2t}\\\\4000=2000(1.045)^{2t}\\\\2=1.045^{2t}\\\\\log_{1.045} 2=2t\\\\t=\frac{\log_{1.045} 2}{2}\\\\t \approx 7.9

5 0
1 year ago
Other questions:
  • A compact-disc case, or jewel case is 14 cm long, 12.5 cm wide, and 1 cm tall. What is the volume of the jewel case?
    15·1 answer
  • A sector with a central angle measure of 200° has a radius of 9 cm. What is the area of the sector?
    10·1 answer
  • What is 5x - 2=13 using the Golden Rule of Equations.
    7·1 answer
  • If C (Circumfrence) = 314 m, what is the area?
    5·1 answer
  • PlZ I WILL GVIE YUO 100 pointd
    6·2 answers
  • Does anyone know what to fill in?
    7·1 answer
  • Fred the farmer had a piece of land shown in which he planted vegetables.
    13·1 answer
  • Slow and steady wins the race. The leatherback sea turtle is the fastest known reptile, with a maximum speed of 21.9221.9221, po
    7·2 answers
  • Which combination of shapes can be used to create the 3-D figure?
    9·2 answers
  • Consider the following number line:
    10·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!