If using the method of completing the square to solve the quadratic equation
x²-10x – 15 = 0, which number would have to be added to "complete the
square"?

Answers

Answer 1

Answer:

For quadratic equations that cannot be solved by factorising, we use a method which can solve ALL quadratic equations called completing the square. We use this later when studying circles in plane analytic geometry.

Completing the square comes from considering the special formulas that we met in Square of a sum and square of a difference earlier:

(x + y)2 = x2 + 2xy + y2 (Square of a sum)

(x − y)2 = x2 − 2xy + y2 (Square of a difference)

To find the roots of a quadratic equation in the form:

\displaystyle{a}{x}^{2}+{b}{x}+{c}={0}ax

2

+bx+c=0,

follow these steps:

(i) If a does not equal \displaystyle{1}1, divide each side by a (so that the coefficient of the x2 is \displaystyle{1}1).

(ii) Rewrite the equation with the constant term on the right side.

(iii) Complete the square by adding the square of one-half of the coefficient of x to both sides.

(iv) Write the left side as a square and simplify the right side.

(v) Equate and solve.

Example 1

Find the roots of x2 + 10x − 4 = 0 using completing the square method.

Answer

Example 2

Solve 4x2 + x = 3 by completing the square.

Answer

Exercises

Solve the following quadratic equations by completing the square

Q1. \displaystyle{2}{s}^{2}+{5}{s}={3}2s

2

+5s=3Answer

Q2. \displaystyle{3}{x}^{2}={3}-{4}{x}3x

2

=3−4xAnswer

Q3. \displaystyle{9}{v}^{2}-{6}{v}-{2}={0}9v

2

−6v−2=0Answer

Q4. \displaystyle{a}{x}^{2}+{b}{x}+{c}={0}ax

2

+bx+c=0Answer

1. Solving Quadratic Equations by Factoring

3. The Quadratic Formula

Answer 2
x²-10x-15 = 0

x² -10x = 15

x² - 10x + 25 = 15 + 25

(x-5)² = 40

x = -2√(10) + 5
x = 2√(10) + 5

Related Questions

A light house worker is tracking a boat that is 5 km south of her. She is also tracking a boat
that is 6 km from the tower located 70° east of north. To the nearest kilometer, how
far apart are the two boats?

A. 7 km
B. 9 km
C. 8 km
D. 16 kM

Answers

Answer:

cccccccccccccccccccccccccccccc c

I generally need help

Answers

Answer:

24 units²

Step-by-step explanation:

4(12)/2=24

whyyyyyy does math suck help meeee plzz

Answers

Do 8+4-7 I learn it that way and it’s correct all the time

Answer:

3 1/2

Step-by-step explanation:

the equation is 7/8x4/1 and can be rewritten as 7x4/8x1 = 28/8 which simplifies to 3 4/8 or 3 1/2

You deposit $500 in an account that earns 6.5% annual interest compounded yearly. Write a function that represents the balance y (in dollars) after x years.

Answers

Answer:

f(x)=.65+y

Step-by-step explanation:

               .

The function for compound interest is A = 500 ( 1.065 )ˣ

What is Compound Interest?

Compound interest is interest based on the initial principle plus all prior periods' accumulated interest. The power of compound interest is the ability to generate "interest on interest." Interest can be added at any time, from continuously to daily to annually.

The formula for calculating Compound Interest is

A = P ( 1 + r/n )ⁿᵇ

where A = Final Amount

P = Principal

r = rate of interest

n = number of times interest is applied

b = number of time periods elapsed

Given data ,

Let the compound interest amount be represented as A

Now , the interest rate r = 6.5 %

The number of times the interest is applied = yearly

The principal amount P = $ 500

n = 1 ( compounded yearly )

t = x ( number of years )

So, the function that represents the balance y (in dollars) after x years is:

y ( x ) = 500 ( 1 + 0.065/1 )ˣ

On simplifying , we get

y ( x ) = 500 ( 1.065 )ˣ

Hence , the function is A = 500 ( 1.065 )ˣ

To learn more about compound interest click :

https://brainly.com/question/21270833

#SPJ2


Mare has a monthly cell phone plan that has a fixed charge of $12 per month plus
$0.30 per text message. Marie wants to spend no more than $40 per month on her
call phone. Which inequality represents the number of text messages, X, that Marie
Please hurry

Answers

You need to multiply the cost per text message by the number of messages (x) add that to the fixed charge.

The total of those need to be less than or equal to the amount she wants to spend.

The equation would be written as:

0.30x + 12 <= 40

I dont really understand this question, can anyone help me out?

Answers

[tex]\mathfrak{\huge{\pink{\underline{\underline{AnSwEr:-}}}}}[/tex]

Actually Welcome to the Concept of the Angles.

Complementary angles sum up together to become 90°.

Supplementary Angles sum up together to become 180°.

hence,

1.) Ans ==>Angle ABC and Angle NMP

2.) Ans ==> angle ABC and angle EFG

Complementary angles add up to 90 degrees while supplementary angles will add up to 180 degrees.

1) ABC & NMP
2) EFG & RST

How can I solve this question?

Answers

draw a rectangle triangle :

sin B=8/17 that means that de biggest side are 17 ("hipotenusa"), and another side is 8. Applying de theorem of pythagoras:

[tex]17^{2} =8^{2} +x^{2} \\x^{2} =17^{2} -8^{2}\\x=\sqrt{17^{2} -8^{2}} \\x=5\sqrt{5}[/tex]

factor out the gcf 12y³+10y²​

Answers

Answer:

Find the prime factors of each term in order to find the greatest common factor (GCF).

2y^2

Factoring out the greatest common factor (GCF)

To factor the GCF out of a polynomial, we do the following: Find the GCF of all the terms in the polynomial. Express each term as a product of the GCF and another factor. Use the distributive property to factor out the GCF.

Step-by-step explanation:

Hope it is helpful.....

The y-intercept is 2.



Question 1 options:
True
False

Answers

Answer:

false. the y-intercept is -2.

False the answer is -2

Which answer choice correctly identifies the missing information in the problem? Joey and Kirk are in the 6th grade. Kirk is 5 feet 4 inches tall. Joey is 4 feet 8 inches tall. How much taller is Kirk than Joey?

Answers

Answer:Kirk is taller than Joey by 8 inches

Step-by-step explanation:

Step 1

Kirk's height is given as  =5 feet 4 inches tall.

Joey's  height 4 feet 8 inches tall

Difference in height = 5 feet 4 inches

                                    - 4 feet   8 inches

                                 =

Step 2

Bear in mind that 12 inches = 1 feet . Now,8 cannot be subtracted from 4 , so we borrow 1 feet from 5feet,  which is equivalent to 12 inches and add to inches  so it becomes

4 feet  (12+4)inches     =                   4 feet     16inches

- 4 feet   8 inches                             - 4 feet   8 inches

                                                     =                   8 inches

Therefore Kirk is taller than Joey by 8 inches

what do you observe about the form of the equation of any circle whose center is at the point of origin​

Answers

Ce clasă ești sa văd daca te pot ajuta

f (x) = 2x g(x) = 4x + 5 Find f (x) + 3g(x)

Answers

Answer:

f(x) + 3g(x) = 14x + 15

General Formulas and Concepts:

Pre-Algebra

Order of Operations: BPEMDAS

Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to Right

Distributive Property

Algebra I

Terms/CoefficientsFunction Notation

Step-by-step explanation:

Step 1: Define

f(x) = 2x

g(x) = 4x + 5

Step 2: Find

Substitute in functions:                                                                                  2x + 3(4x + 5)[Distributive Property] Distribute 3:                                                               2x + 12x + 15Combine like terms:                                                                                       14x + 15

x^2+17x+4=0 find the discriminant.

Answers

273 I hope this helps out buddy :)
The person above me is correct!

[
1
What is the distance between the points (-4, -8) and (10,-8)?
Need help

Answers

Answer:

2

Step-by-step explanation:

√(-8-8)^2 +(10+4)^2=

✓-32+28

✓4

=2

Question: 2 out of 10
~!¡! Volume !¡!~
(Pleaaase go try to answer the first one- )

Answers

Answer:

B) 2,340

Step-by-step explanation:

Find and reduce -4/7 x 2/3

What is the answer to this?

Answers

Answer:

-8/21

Step-by-step explanation:

The answer to your asked question is -8/21

I’m confused about this problem

Answers

Cosx=180/114

X= cos inverse 180/114

You know how to do cos inverse on the calculator??or should i tell you?

x= arctan (114/180)

=32.34744..

rounded to the nearest tenth =32.3

Step-by-step explanation:

At 6:00 A.M., the temperature was 10º below zero. During the day, the temperature rose an average of 2º per hour. If h represents the number of hours since 6:00 A.M., which equation represents the temperature T?

Answers

Answer:

t=-10+2h

Step-by-step explanation:

How do I write a phrase in words as an algebraic expression for 8/d?

Answers

Answer:

The quotient of 8 and d.

Step-by-step explanation:

I hope this helps you have a wonderful day! :D

give all relationships between angle 1 and angle 2 select all that apply​

Answers

Answer:

vertical maybe if try it and see

Help me please!!!!!!

Answers

Answer:

(2,8)

Step-by-step explanation:

I'm not so sure but if I were answering I would have picked (2,8)

Answer the photo below thanks

Answers

Answer:

x=50

Step-by-step explanation:

65+65=130

180-130=50

Answer:

50 is the answer

Step-by-step explanation:

this is a isosceles triangle having 65 and 65

then 65 + 65 + x = 180 property of traingle

130 + x = 180

x = 180- 130 = 50

The part that's cut off it says To the nearest tenth of a percent, what's percent... ​
and is the answer 3.3?

Answers

Answer:

Yes you are correct.

El alcance de tangente

Answers

Answer: ¿Qué significa alcance tangente? ¡Lo busqué y no dice nada!

Step-by-step explanation:

There is an unknown number of people at the table at the
beginning of lunch. Then...
3 more people joined the group.
Then the entire group divided into 2 groups, and
one group left and went outside,
of the total students were left in the lunchroom
5 people joined the group in the lunchroom.
The total number of people in the lunchroom at the
end of lunch was 10

a. Write the equation you can create to show this situation.

b. How many people were at the table at the beginning of lunch? Explain how you know.

Answers

Answer:

11 hours ago u prob dont need it

Step-by-step explanation:

123456

flora has a summer job where she earns $9.50 per hour. At this company, employees get a 10% raise after working for 400 hours. If flora works 640 hours over the summer, how much money will she make?

Answers

So if she works 640 hours we need to find out how much of that gets the 10% raise
640-400=240
So 240 hours get a 10% raise
400 • $9.50= $3,800
To find out how much the raise effects it
$9.50 • 10%= $0.95 + $9.50= $10.45
So the rates for the hours over 400 are $10.45
240 • $10.45=$2,508

$2,508 + $3,800= $6,308
So she made $6,308

25a² -4b²+28bc-49c² factorize​

Answers

Step-by-step explanation:

Since both terms are perfect squares, factor using the difference of squares formula,

Step-by-step explanation:

= 25 a²- ( 4b²- 28bc +49c²)

=. 25a²- {( 2b)²- 2(2b)(7c)+ (7)²}

= 25a²- { (2b - 7c)²}

= (5a)²- (2b -7c)²

= { 5a -(2b-7c)} { 5a+ ( 2b-7c)}

= ( 5a - 2b +7c) ( 5a +2b - 7c)

plz mark my answer as brainlist plzzzz.

hope this will be helpful to you .

plz you find it useful plz mark my answer as brainlist.

what 2/5(10x + 3/4) - 2x? ​

Answers

Answer:

2x + 3/10

Step-by-step explanation:

2/5 (10x + 3/4) - 2x = 4x + 3/10 - 2x = 2x + 3/10

HELP I NEED HELP ASAP

A. Day 4 to Day 6
B. Day 8 to Day 10
C. Day 6 to Day 8
D. Day 10 to Day 12

Answers

Answer:

b

Step-by-step explanation:

trust i did it already

Answer:

the answer is B

Step-by-step explanation:

I just had that question

does anyone know the answer to 5(2t+3)=75 that can tell me how to find the answer not just the answer

Answers

Answer: Let me know if this helps.

Step-by-step explanation:

5(2t+3)=75     Distribute the 5 using multiplication. 5x2t and 5x3

10t+15=75      Subtract 15 because you need to get the t by itself.

10t = 60         Now divide by 10 to get t by itself. 10/10 and 60/10.

t = 6               Answer.

Answer:

t=6

Step-by-step explanation:

It's all about get t on one side of the equation, and so everything else on the other side of the equation.

The first thing we want to get rid of is the 5. The 5 is multiplied by (2t+3), so to get rid of it, we divide both sides by five (divide both sides since they must remain equal):

(5(2t+3))/5=75/5

2t+3=15

The next thing we can get rid of is the 3. Subtract 3 from both sides:

2t+3-3=15-3

2t=12

Now, we get rid of the 2. Divide both sides by 2:

2t/2=12/2

t=6

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