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
Ne4ueva [31]
3 years ago
9

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:
zlopas [31]3 years ago
5 0

Answer:

  • <u>80km/h and 60km/h</u>

Explanation:

<u>1. Data:</u>

i) Distance traveled by the cars:

  • d = 780 km

ii) Speed of the cars:

  • v₁ and v₂
  • v₁ = v₂ + 20 km/h

iii) Time to arrive at the suburb:

  • t₂ - t₁ = 2 hour ⇒ t₂ = t₁ + 2

<u>2. Equations:</u>

  • speed = distance / time

        time  = distance / speed

  • t₂ = 480 / v₂
  • t₁ = 480 / v₁ = 480 / (v₂ + 20)

               t₂        -       t₁                =  2 hour

               ↓                 ↓                    ↓

           480/v₂    -  480/ (v₂ + 20) =  2

             

<u>3. Solve the equation</u>

     480(v₂ + 20) - 480(v₂) =  2 × (v₂ + 20) (v₂)

     240(v₂ + 20) - 240(v₂) =  (v₂ + 20) (v₂)

     240v₂ + 4800 - 240v₂ =  (v₂)²  + 20v₂

      (v₂)²  + 20v₂ - 4800 = 0

      (v₂ + 80) (v₂ - 60) = 0

      v₂ = - 80

      v₂ = 60

Only the positive solution has physical meaning:

  • v₂ = 60km/h                                      ← answer
  • v₁ = 60km/h + 20km/h = 80km/h     ← answer
You might be interested in
HELP ASAP I HAVE TO GET IT DONE<br><br><br> Solve for x in the diagram below
MA_775_DIABLO [31]

Answer:

x = 35

General Formulas and Concepts:

<u>Pre-Algebra</u>

  • Order of Operations: BPEMDAS
  • Equality Properties

<u>Geometry</u>

  • Definition of a Line: A line is 180°

Step-by-step explanation:

<u>Step 1: Set up equation</u>

40° + (2x + 30)° + 40° = 180°

<u>Step 2: Solve for </u><em><u>x</u></em>

  1. Combine like terms:                    2x + 110 = 180
  2. Subtract 110 on both sides:         2x = 70
  3. Divide 2 on both sides:               x = 35
7 0
2 years ago
Please help i've been stuck on these for a bit now!
lisov135 [29]

Answer:

Q6. D

Q8. A

Step-by-step explanation:

Q6. In 40 trials, he flipped '2 heads and 1 tail' 16 times.

For 2 heads, probability= 16/40= 4/10

For 120 trials, number of times= 4/10 × 120= 48

Q8.

125x + 200 \geqslant 1200 \\ 125x \geqslant 1200 - 200 \\ 125x \geqslant 1000 \\ x \geqslant 1000 \div 125 \\ x \geqslant 8

Answer is A because the inequality shows that x is equal or greater than 8 so the dot at 8 has to be coloured.

Note that we do not change the inequality sign unless we are dividing the whole thing by -1.

5 0
3 years ago
What should be included ina financial plan to protect assets?
pantera1 [17]

Answer:

b

Step-by-step explanation:

its important to have a large savings so that if something happens & it's an emergency, you can touch THOSE funds and not your assets, which may lose you money.

5 0
3 years ago
Read 2 more answers
What is the defination of the focus when referring to a parabola?
Len [333]

Answer:

Focus of a Parabola. A parabola is set of all points in a plane which are an equal distance away from a given point and given line. The point is called the focus of the parabola and the line is called the directrix. The focus lies on the axis of symmetry of the parabola.

Step-by-step explanation:

6 0
3 years ago
Who has the ps5 i do
Rzqust [24]

Answer:

im from da fam round herrrr u either got the ps3 or the x box 3-60

lm.ao.

4 0
3 years ago
Other questions:
  • What is the simplest form of the expression?
    8·1 answer
  • Find the value of x in the isosceles triangle shown
    15·1 answer
  • V(t)=125t^2-3000t+22000
    9·1 answer
  • Solve for x.<br> x/4≥−8<br><br> A.) x≤−32<br><br> B.) x≤−2<br><br> C.) x≥−32<br><br> D.) x≥−2
    8·1 answer
  • Find the perimeter of the following isosceles triangle. show work
    14·1 answer
  • What percentage is .0019951
    15·2 answers
  • A river 3m deep and 40 m wide is flowing at the rate 2km /h . how much water will fall into the sea in a minute.​
    8·2 answers
  • Solve each system by substitution. Show your work.
    13·1 answer
  • Please help me i’ll give brainlist and points
    10·1 answer
  • Please helpppppppppp
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!