Solve x2 + 18x – 19 = 0 by completing the square.

Answers

Answer 1

Answer:

x = 1, x = -19

Step-by-step explanation:

1) factorise

(x−1)(x+19)=0

2) equal to 0

x−1=0 or x+19=0

x=1 or x=−19

Answer 2

Answer:

[tex]x = 1[/tex]

[tex]x = 19[/tex]

Step-by-step explanation:

Set up equation

[tex] {x}^{2} + 18x - 19 = 0[/tex]

Add 19 on both sides

[tex] {x}^{2} + 18x = 19[/tex]

Divide 18 by 2 and sqr it.

[tex]( \frac{18}{2}) {}^{2} [/tex]

[tex] {9}^{2} = 81[/tex]

Add 81 on both sides

[tex] {x}^{2} + 18x + 81 = 100[/tex]

Using the AC method, isolate the left side into a binomial.

[tex](x + a)(x + b)[/tex]

that a and b can be added to equal 18 and be multiplied to equal 81.

Only number that does that is 9. 9+9=18, 9×9=81

[tex](x + 9)(x + 9)[/tex]

[tex](x + 9) {}^{2} [/tex]

Set up equation

[tex](x + 9) {}^{2} = 100[/tex]

Take sqr root of both sides

[tex]x + 9 = 10[/tex]

Since sqr root of a positve number can be negative, set up this equation also

[tex]x - 9 = 10[/tex]

[tex]x = 1[/tex]

OR

[tex]x = 19[/tex]


Related Questions

Volume!!! will give brainly thing if correct!

please how your work if possible

Answers

Answer:

C

Step-by-step explanation:

The picture give you the law of the volume of the pyramid

please help me with these two problems​

Answers

Problem 1

With mean = median, the data set is symmetrical. Well it's more accurate to say "roughly symmetrical" due to the phrasing "mean is approximately equal to the median". Using the median as its center is fairly common with many distributions, so there isn't an issue here.

The error is from the phrasing "the quartiles should be used to measure the spread". The quartiles themselves don't measure spread. They are simply single data points and do not tell us the spread. If Ralph said Q3 = 75 is a measure of spread, then he would be incorrect. However, the difference between the third and first quartile will help get the IQR (interquartile range), as described by this equation below

IQR = Q3 - Q1

and this is one tool to measure how spread out data is. The larger the IQR is, the more spread out the data will be.

The IQR is how far of a gap it is from Q1 to Q3. Another tool to measure spread is the standard deviation. Ralph was probably thinking about the IQR when he mentioned the quartiles, but he should be more specific about what he means.

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

Problem 2

Answer: Skewed left

This is the same as saying "negatively skewed"

---------------

Explanation:

The main cluster of values is on the right side, while a small portion of values are to the left. We consider this the left tail and the left tail is pulled longer compared to the right tail. The further left we go, the shorter the bar and eventually we hit outliers. These much smaller outliers compared to the main cluster pull on the mean to make it smaller than it should be.

One example could be that this curve represents test scores. The majority of the class could get in the range of say 70 to 90. Then there's the unfortunate few outliers who scored much lower (possibly 40 through 60); those outlier scores pull down the mean grade of the class overall.

In short, negatively skewed data indicates that mean < median.

HHHEEELLLPPPPP MMMMMMEEEEEE!!!!!!

Which is the graph of the function g(x)=−x^2−4x−1?

Answers

Answer:

its a, the first one

Step-by-step explanation:

i graphed it have a good day (:

Determine The Missing Number In The equation

1+12= +2


PLEASE HURRY!!!!

Answers

I guess it is 13, 1 plus 12 is 13 so

Which of the following equations is the result after the first step in solving 3x + 6 = 12?
x + 6 = 4
x = 3
3x = 18
3x = 6

Answers

Answer:

3x =6

Step-by-step explanation:

3x+6 =12

Subtract 6 from each side

3x+6-6 = 12-6

3x =6 pls mark branilest if that helped

For his car Jason paid 91.48 per speacker for 3 speackers and 92.55 per tire for 5 tires with 8 100 bills . How much did Jason get in change ?

Answers

Answer:

1 speaker is $91.48

3 speakers = $91.48 × 3

= $274.44

1 tire is 9$2.55

5 tires = $92.55 × 5

= $462.75

8, 100 bills = $800

The cost for the 3 speakers and 5 tires = $274.44 + $462.75

= $737.19

Therefore, the change that Jason got was = $800 - $737.19

= $62.81

Salim buys boxes of crackers that each has the same cost x. He represents the cost of 3 boxes of
cheese crackers, 4 boxes of poppy seed crackers, and 6 boxes of plain crackers using the
expression 3x + 4x + 6x. What equivalent expression can represent the cost?​

Answers

Answer:

13x

Step-by-step explanation:

You add them all up since they're like terms and all have x

pls help with this question i cant solve it

Answers

The tree is 6 feet tall

absolute value of -93​

Answers

The absolute value will be the positive version of the number
absolute value of -93 will be 93

Answer:

93

Step-by-step explanation:

The absolute value is just how far from away from zero a number is.

I need help with this right now before it’s due
Grapes

Answers

Answer:

21, 6, 12

Step-by-step explanation:

your welcome:)

14:7, 42:21, 6:3, 12:24
14/7=2
42:2=21
3•2=6
24/2=12
Missing numbers are: 21,6 and, 12

Solve for x. 4(3x - 5) = 7(2x + 3).

Answers

Answer:

x = -20.5

Step-by-step explanation:

Simplifying

4(3x + -5) = 7(2x + 3)

Reorder the terms:

4(-5 + 3x) = 7(2x + 3)

(-5 * 4 + 3x * 4) = 7(2x + 3)

(-20 + 12x) = 7(2x + 3)

Reorder the terms:

-20 + 12x = 7(3 + 2x)

-20 + 12x = (3 * 7 + 2x * 7)

-20 + 12x = (21 + 14x)

Solving

-20 + 12x = 21 + 14x

Solving for variable 'x'.

Move all terms containing x to the left, all other terms to the right.

Add '-14x' to each side of the equation.

-20 + 12x + -14x = 21 + 14x + -14x

Combine like terms: 12x + -14x = -2x

-20 + -2x = 21 + 14x + -14x

Combine like terms: 14x + -14x = 0

-20 + -2x = 21 + 0

-20 + -2x = 21

Add '20' to each side of the equation.

-20 + 20 + -2x = 21 + 20

Combine like terms: -20 + 20 = 0

0 + -2x = 21 + 20

-2x = 21 + 20

Combine like terms: 21 + 20 = 41

-2x = 41

Divide each side by '-2'.

x = -20.5

if a shuttle can go 28,000km per hour, how long will it take for the shuttle to go 1,277,127,530 km?

Answers

You should divide 1277127530/28000= 45611.6975km
1,277,127,530km/28,000km per hr=
45,611.6975 hrs

Distribute: -8(3f - 9)

Answers

Step-by-step explanation:

[tex] - 8(3f - 9) = [/tex]

[tex] - 24f + 72[/tex]

Pollsters are concerned about declining levels of cooperation among persons contacted in surveys. A pollster contacts 76 people in the 18-21 age bracket and finds that 65 of them respond and 11 refuse to respond. When 281 people in the 22-29 age bracket are contacted, 263 respond and 18 refuse to respond. Assume that 1 of the 357 people is randomly selected. Find the probability of getting someone in the 22-29 age bracket or someone who agreed to respond.

Answers

Answer:

0.9692 = 96.92% probability of getting someone in the 22-29 age bracket or someone who agreed to respond.

Step-by-step explanation:

A probability is the number of desired outcomes divided by the number of total outcomes.

Find the probability of getting someone in the 22-29 age bracket or someone who agreed to respond.

357 people.

281 in the 22-29 age bracket + 65 in the 18-21 that agree to respond. So

[tex]p = \frac{281+65}{357} = 0.9692[/tex]

0.9692 = 96.92% probability of getting someone in the 22-29 age bracket or someone who agreed to respond.

Given that n is an integer, prove that 6 is a factor ofn3+ 5n

Answers

Answer:

n3+5n=6

taking common as n

n(5+3)=6

n8=6

A man has 1/2 of a kilogram of rice. He shares it equally amongst 6 people. How many kilograms does each person get? Input your answer as a fraction of a kilogram.

Answers

Answer:

1/12

Step-by-step explanation:

The graph of y=f(x) is shown below. According to the graph what is f(3)?

Answers

f(3) is equal to -4 or letter b coordinate

Pls Hurry its timed

How do the number line graphs of the solutions sets of Negative 23 greater-than x and x greater-than-or-equal-to negative 23 differ?

A One graph uses an open circle, but the other graph uses a closed circle. Also, the rays use arrows that point in opposite directions, but they have the same endpoint.

B They use arrows that point in opposite directions, the rays have different endpoints, and both graphs use open circles.

C One graph uses an open circle, but the other graph uses a closed circle. Also, the rays have different endpoints, but they use arrows that point in the same direction.

D They use arrows that point in opposite directions, the rays have different endpoints, and both graphs use closed circles.

Answers

I’m pretty sure it’s A

According to a survey, about 19% of all Americans are without health insurance. Assume that this estimate is reasonably accurate. Suppose that you select a random sample of 46 Americans. (a) Calculate the expected number of Americans without health insurance in the sample. Answer: (Keep at least four decimal places.) (b) Calculate the standard deviation of the number of Americans without health insurance in the sample. Answer: (Keep at least four decimal places.)

Answers

Answer:

a) 8.74

b) 2.6607

Step-by-step explanation:

For each American, there are only two possible outcomes. Either they are without health insurance, or they are not. In the sample, each person is independent of any other person, which means that we use the binomial probability distribution to solve this question.

Binomial probability distribution

Probability of exactly x sucesses on n repeated trials, with p probability.

Can be approximated to a normal distribution, using the expected value and the standard deviation.

The expected value of the binomial distribution is:

[tex]E(X) = np[/tex]

The standard deviation of the binomial distribution is:

[tex]\sqrt{V(X)} = \sqrt{np(1-p)}[/tex]

According to a survey, about 19% of all Americans are without health insurance.

This means that [tex]p = 0.19[/tex]

Suppose that you select a random sample of 46 Americans.

This means that [tex]n = 46[/tex]

(a) Calculate the expected number of Americans without health insurance in the sample.

[tex]E(X) = np = 46*0.19 = 8.74[/tex]

(b) Calculate the standard deviation of the number of Americans without health insurance in the sample.

[tex]\sqrt{V(X)} = \sqrt{np(1-p)} = \sqrt{46*0.19*0.81} = 2.6607[/tex]

Which side length is labeled correctly?
A 3cm
B 4cm
C 5cm
D None are correctly labeled

Answers

Answer:

Step-by-step explanation:

3 cm

8^10 x 8^4 simplified write your answer as a power

Answers

Answer: 8^14

8^10 x 8^4= 8^14

Answer:

8^14

Step-by-step explanation:

8^10x8^4=8^(10+4)=8^14

One half of an apple pie is left for
5 family members to share equally.
What fraction of the original pie will
each member get?

Answers

Answer: It will be 2/10

Step-by-step explanation:because if you divide the half part that you have into five and the other one two you will have 10 pieces that divided into 5 members will be 2

A real estate agent has 17 properties that she shows. She feels that there is a 50% chance of selling any one property during a week. The chance of selling any one property is independent of selling another property. Compute the probability of selling less than 3 properties in one week. Round your answer to four decimal places.

Answers

Answer:

0.0011 = 0.11% probability of selling less than 3 properties in one week.

Step-by-step explanation:

For each property, there are only two possible outcomes. Either they are sold, or they are not. The chance of selling any one property is independent of selling another property. This means that the binomial probability distribution is used to solve this question.

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

In which [tex]C_{n,x}[/tex] is the number of different combinations of x objects from a set of n elements, given by the following formula.

[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]

And p is the probability of X happening.

A real estate agent has 17 properties that she shows.

This means that [tex]n = 17[/tex]

She feels that there is a 50% chance of selling any one property during a week.

This means that [tex]p = 0.5[/tex]

Compute the probability of selling less than 3 properties in one week.

This is

[tex]P(X < 3) = P(X = 0) + P(X = 1) + P(X = 2)[/tex]

In which

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

[tex]P(X = 0) = C_{17,0}.(0.5)^{0}.(0.5)^{17} \approx 0[/tex]

[tex]P(X = 1) = C_{17,1}.(0.5)^{1}.(0.5)^{16} = 0.0001[/tex]

[tex]P(X = 2) = C_{17,2}.(0.5)^{2}.(0.5)^{15} = 0.0010[/tex]

[tex]P(X < 3) = P(X = 0) + P(X = 1) + P(X = 2) = 0 + 0.0001 + 0.0010 = 0.0011[/tex]

0.0011 = 0.11% probability of selling less than 3 properties in one week.

5. The area of the greatest square that is cut from a rectangle of sides
7cm and 4cm is
(1)
49sq.cm (ii) 28sq.cm (iii) 16sq.cm (iv) 9sq.em

Answers

Answer:

16 cm²

Step-by-step explanation:

The dimension of rectangle = 7cm by 4 cm

The Area of the greatest square that can be cut from the rectangle :

The dimension has to be the Same to form a square :

Hence, the greatest width = 4cm

Therefore, taking the length also as 4cm

Area of square = side length²

Greatest area of square that can be cut = 4² = 16cm²

2/5 times 20 can you please help

Answers

Answer:

8

Step-by-step explanation:

The answer is 8 multiple

Hope it helps

PLS ANSWER ASAP THANKS

Answers

Answer:

x=54°

Step-by-step explanation:

x+36°=90°

x=90°-36°

x=54°

HOPE IT HELPS U

HAVE A GREAT DAY

How to Write in Digits the fifty five hundredths​

Answers

Answer:

fifty five hundredths = 0.55

Step-by-step explanation:

Let's use 0.45 as an example. You read this decimal by using the place value of the last digit to the right of the decimal point.

This number is read as forty-five hundredths because the last digit is in the hundredths place.

What are the coordinates of point of intersection of y=x+3 and y=3x-3?

Answers

Answer:

Correct option is

D

(0, 0)

Form the graph, we can see that solution is (0,0).

or

The point of intersection of lines y = 3x and x = 3y must satisfies both the equation.

From the options (0,0) satisfies both the equations, hence the point of intersection of given lines is at origin i.e. (0,0).

Answer:

Step-by-step explanation:

At the point of intersection, x+3 = 3x-3

6=2x

x = 3

y = x+3 = 6

Find y if the line through (5, 2) and (7, y) has a slope of 4.

Y= ___

Answers

y=10

(y-2):(7-5)=4
y-2=4(7-5)
y-2=28-20
y=8+2
y=10

Find a function for the graph below

Answers

Answer:

d

Step-by-step explanation:

gfstikuhbbcwdjonngbb1519360

Answer:

D

Step-by-step explanation:

I took multivariable calculus in hs

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