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
solmaris [256]
3 years ago
10

Which of these choices are quadratic equations? Check all that apply.

Mathematics
2 answers:
balandron [24]3 years ago
3 0

Answer:

A

Step-by-step explanation:

SVETLANKA909090 [29]3 years ago
3 0

Answer:

<em>Quadratic Equations ⇒ D, E, F</em>

Step-by-step explanation:

Let us say that each of these equations can only be defined as a quadratic equation if it can be factored / solved through completing the square / application of quadratic formula as solve for the value of x;

A. 2x - 1 = 0, Add + 1 to either side,\\2x = 1, Divide sides by 2,\\x = 1 / 2 ; Not Quadratic Equation

B. 2x^2 - 1 = 0, Add + 1 to either side,\\2x^2 = 1, Divide sides by 2,\\x^2 = 2, Take | | of x, \sqrt{x} - either side \\\| x | = \sqrt{1 / 2},\\x = \sqrt{1 / 2}  = -  \sqrt{1 / 2} ; NotQuadraticEquation

C. 2x^2 - 1, NotInForm - ax^2 + bx + x = 0 ; NotQuadraticEquation

D. 3x^2 + 5x - 1 = 0, Add 1 to either side,\\3x^2 + 5x = 1, Divide sides by 3,\\x^2 + 5x / 3 = 1 / 3, Solve for a,\\2ax = 5 / 3x, Divide sides by 2x,\\a = 5 / 6, Add a^2 - ( 5 / 6 )^2 to either side,\\x^2 + ( 5x / 3 )^2 + ( 5 / 6 )^2 = 1 / 3 + ( 5 / 6 )^2, simplify,\\( x + 5 / 6 )^2 = 37 / 36, solve for x,\\x = ( \sqrt{37} - 5 ) / 6 = ( - \sqrt{37} - 5 ) / 6 ; QuadraticEquation

E. x - x^2 + 5 = 0, Similar Form ; QuadraticEquation\\

F. - 4x^2 + x = 0, Factor the Expression,\\- x * ( 4x - 1 ) = 0, Apply Zero Product Property,\\x = 0, and, 4x - 1 = 0,\\x = 0 = 1 / 4 ; QuadraticEquation

You might be interested in
Some help with this pleaseee!
lakkis [162]

Answer:

g(x) = |x| + 7

Step-by-step explanation:

Adding the constant +7 on the end of the equation means a translation 7 units up.

6 0
3 years ago
| 9. The distance between Town A and Town B was 108 km. A car and a van left Town A at 12 00 for Town B. On reaching Town B, the
Westkost [7]

Answer:

a)  Time until both vehicles meet is 1.5 hours after starting at noon.  That makes it 1:30PM.

b)  Average speed of car is 84 km/h

Step-by-step explanation:

A -----------------------z------------B

          <u>Left</u>      <u>Speed(km/h)</u>      <u>Time</u>

Car:   12PM            X  

Van:   12PM           60

Car/Van

DistanceCar        AB + z

DistanceVan       Az

Ratio:                  (AB+z)/Az  = 7/5

Time until both meet = T (in hours)

Distance Car:            xT

Distance Van:           60T

====

  xT = AB + z

  60T = Az

---

(xT/60T)= (7/5)

x = 60(7/5)

x = 84 km/h

=====

Time for car to reach B is:    time (hr) = 108 km/(84 km/h)

                                                 time = 1.286 hours

Distance for at 1.289 hours is:    distance (km) = (60 km/h)*(1.286 h)

                                                   distance = 77.14 km

At 1.286 hours, the car reverses direction.  The van is (108 km - 77.14 km) or 30.86 km away.

Add the distances travelled by both vehicles after the car reverses direction at 1.286 hours.  The sum will be 30.86 km when they meet, at time of T.

Car Distance + Van Distance = 30.86 km

T(84 km/h) + t(60 km)

They meet when they are 0 km apart, which can be modeled with the following equation:

Van travel Distance - Car Travel Distance = 0 starting at 1.286 hr.

Let <u>t</u> be the time <u>after</u> 1.286 hours that both vehicles meet/collide.

t*(60 km/h)  +  t(84 km/h) = 30.86 km

t(60+84) = 30.86 km

t(144 km/h) = 30.86 km

t = 0.2143 hr

Total time until the car and van meet is 1.286 hr + 0.2143 hr for a total of 1.50 hours.

=================

a)  Time until both vehicles meet is 1.5 hours after starting at noon.  That makes it 1:30PM.

b)  Average speed of car is 84 km/h

==============

<u>CHECK</u>

Is the ratio of the distance travelled by the car and the van until they meet in the ratio of 7/5?

Car distance is (1.5 hr)(84 km/h) = 126 km

Van distance is (1.5 hr)(60 km/h) = 90.0 km

Ratio is 126/90 or 1.4

Ratio of 7/5 is 1.4

<u><em>YES</em></u>

     

3 0
2 years ago
The size of angle aob is equal to 132 degrees and the size of angle cod is equal to 141 degrees. find the size of angle dob.
Varvara68 [4.7K]

angle AOB = 132 and is also the sum of angles AOD and DOB. Hence 
angle AOD + angle DOB = 132°    ---> 1 

angle COD = 141 and is also the sum of angles COB and BOD. Hence 
angle COB + angle DOB = 141°    ---> 2

Now we add the left sides together and the right sides of equations 1 and 2 together to form a new equation. 

angle AOD + angle DOB + angle COB + angle DOB = 132 + 141       ---> 3 

We should also note that: 
angle AOD + angle DOB + angle COB = 180° 

Therefore substituting angle AOD + angle DOB + angle COB in equation 3 by 180 and solving for angle DOB:
180 + angle DOB = 132 + 141 
angle DOB = 273 - 180 = 93° 

8 0
3 years ago
The ratio of pencils to erasers is 4:1. if there are 20 pencils, how many erasers are there?
serious [3.7K]
5 Erasers, 4:1 is equal to 20:5, if you just multiply both numbers by 5
7 0
3 years ago
Read 2 more answers
What is PA <br> Enter your answer in the box
SSSSS [86.1K]

Answer:

3

Step-by-step explanation:

P is the in-center

⇒PA=PE=PD because they are in-radius of the in-circle

We know that, tangent segments drawn from a point outside the circle are always equal in length

⇒DK=EK=7.2

In right triangle PKE,

using Pythagoras' Theorem : PK^{2}=PE^{2}+KE^{2}

⇒PE^{2}=PK^{2}-KE^{2}

⇒PE=\sqrt{PK^{2}-KE^{2} }

⇒PE^{2}=\sqrt{7.8^{2}-7.2^{2}} }

⇒PE=3

Therefore, PA=3

3 0
3 years ago
Other questions:
  • A gardener is planting two types of trees:
    6·1 answer
  • State whether the equation represents exponential growth, exponential decay, or neither. y=2*0.68^x
    8·2 answers
  • Riley is saving up to buy a new television. She needs a total of $968.58. Riley has saved $200.78 already and earns $76.78 per w
    12·1 answer
  • Han ran 10 meters in 2.7 seconds. Priya ran 10 meters in 2.4 seconds. How long would it take han to run 50 meters.
    11·1 answer
  • You have a 3 card deck containing a king, a queen, a jack. You draw a random card. Without putting it back, you draw a random se
    14·2 answers
  • What percent of students prefer burgers?
    10·1 answer
  • I have finals pls help​
    5·2 answers
  • mercer middle school has 1400 students last year this year there are 1,120 students enrolled. Find the percent of change in the
    9·1 answer
  • 26. Consider the irregular figure.
    13·1 answer
  • Pls help ill kiss u
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!