solve using substitution
x^2 -4x+20=0

Answers

Answer 1

Answer:

Step-by-step explanation:

x^2 - 4x + 20 = 0

x^2 - 4x = -20

x^2 = 4x - 20

x = 2x - 4.47

-3x = -4.47

x = roughly 1.5


Related Questions

which number will make the two fractions equivalent? 70/84=5/?

Answers

Answer:

6

Step-by-step explanation:

70/84 = 5/N

70N = 420

N = 420/70 = 6

Maggie picked 2/5 basket of strawberries and Sally picked 2/4. How much more did Sally pick?

Answers

Answer:

Step-by-step explanation:

2/5 = 0.4

2/4 = 0.5

0.5 - 0.4 = 0.1

Sally picked 1/10 of a basket more than Maggie picked

Answer:

1 this could change depending on how many berries are in each basket

Step-by-step explanation:

2/5 = 0.4

2/4 = 0.5

Principle $1950 rate 4 1/2% time 9

Answers

Answer:

Interest = [tex] \boxed{\$ 789.75} [/tex]

Explanation:

Interest [I] = principle × rate × time [prt]

______________________________

x% = x/100

a b/c = a + (b/c) = (ac + b) / c

______________________

I = prt

I = ($1,950)(4 ½%)(9)

I = ($1,950)(0.045)(9)

I = ($87.75)(9)

I = ($789.75)

I = $789.75

The cost c (in dollars) for the fuel and maintenance of a go-cart is given by c=9x+1500, where x is the number of rides. It costs $34 per ride. How many rides does it take to break even?

Answers

Step-by-step explanation:=x1430

What is the value of the expression 1/2x2/5 ÷2/6

Answers

Answer: 3/5 (0.6 decimal form)

Step-by-step explanation:

Question
Find the third degree polynomial function that has an output of 320 when x = 4, and has zeros 2 and
-8i

Answers

Answer:

[tex]f(x)=2(x-2)(x^2+64)[/tex]

Step-by-step explanation:

A standard polynomial in factored form is given by:

[tex]f(x)=a(x-p)(x-q)...[/tex]

Where p and q are the zeros.

We want to find a third-degree polynomial with zeros x = 2 and x = -8i and equals 320 when x = 4.

First, by the Complex Root Theorem, if x = -8i is a root, then x = 8i must also be a root.

Therefore, we acquire:

[tex]f(x)=a(x-(2))(x-(-8i))(x-(8i))[/tex]

Simplify:

[tex]f(x)=a(x-2)(x+8i)(x-8i)[/tex]

Expand the second and third factors:

[tex]=(x+8i)x+(x+8i)(-8i)\\\\=(x^2+8ix)+(-8ix-64i^2)\\\\=(x^2)+(8ix-8ix)+(-64i^2)\\\\=x^2-64(-1)\\\\ =x^2+64[/tex]

Hence, our function is now:

[tex]f(x)=a(x-2)(x^2+64)[/tex]

It equals 320 when x = 4. Therefore:

[tex]320=a(4-2)(4^2+64)[/tex]

Solve for a. Evaluate:

[tex]320=(2)(80)a[/tex]

So:

[tex]320=160a\Rightarrow a=2[/tex]

Our third-degree polynomial equation is:

[tex]f(x)=2(x-2)(x^2+64)[/tex]

Answer:

f(x)=2(x-2)(x^2+64)

Step-by-step explanation:

Recently many companies have been experimenting with telecommuting, allowing employees to work at home on their computers. Among other things, telecommuting is supposed to reduce the number of sick days taken. Suppose that at one firm, it is known that over the past few years employees have taken a mean of 5.4 sick days. This year, the firm introduces telecommuting. Management chooses a simple random sample of 80 employees to follow in detail, and at the end of the year, these employees average 4.5 sick days with a standard deviation of 2.7 days.
a) Describe the population in the context of this problem
b) Describe the parameter u in the context of this problem.
c) Describe the sample in the context of this problem.
d) Describe the statistic in the context of this problem
e) The firm would like to know if there is evidence that the true mean number of sick days for all employees of the firm has decreased after telecommuting was introduced. State the hypotheses. Use ?-0.10.
f) Check the assumptions. If you don't know if an assumption is satisfied based on the information provided, then state "We must assume
g) Calculate the test statistic
h) Find the p-value.
i) Make a decision.
j) State the conclusion in terms of the problem.

Answers

Answer:

A.) Population : All employees at a firm

B.) μ = 5.4

C.) Sample : 80 employees at a firm

D.) Sample mean, x bar = 4.5

Step-by-step explanation:

From the question :

E.)

H0: μ ≥ 5.4

H1 : μ < 5.4

F.)

If Pvalue < α ; Reject H0

G.)

Test statistic :

(xbar - μ) ÷ (s/sqrt(n))

(4.5 - 5.4) ÷ (2.7/sqrt(80))

-0.9 ÷ 0.3018691

= - 2.98

H.)

Pvalue fro Zscore calculator, α = 0.10 = 0.002882

I.)

Decision :

0.002882 < 0.10

Since, Pvalue < α ; We reject the Null

J.)

We Can conclude that the true mean number of sick days for all employees of the firm has decreased after telecommuting was introduced

25 liters of water are pumped into a dam in 20 seconds

how much water will be pumped in within 3 minutes???​ help please

Answers

1 minute = 60 seconds.

3 minutes x 60 seconds = 180 seconds.

180 seconds / 20 = 9

25 liters x 9 = 225

Total water in 3 minutes = 225 liters

Answer:

225 liters

Step-by-step explanation:

There is 25 liters in 20 seconds, so you keep adding 20 seconds while adding 25 liters each time. 180 = 3 minutes

25   20

50   40

75   60

100  80

125  100

150  120

175   140

200  160

225  180

2. Write a polynomial function of least degree with rational coefficients so that P(x)=0 has the given root.
4 - 5i

Answers

Answer:

p(x) = x^2 - 8x + 41

Step-by-step explanation:

If a polynomial with rational coefficients has a complex root, then the roots come in complex conjugate pairs. If the polynomial we need to find has the root 4 - 5i, then it must also have its complex conjugate 4 + 5i as a root.

p(x) = [x - (4 - 5i)][x - (4 + 5i)]

p(x) = [(x - 4) + 5i][(x - 4) - 5i]

Now it's a difference of two squares.

p(x) = (x - 4)^2 - (5i)^2

p(x) = x^2 - 8x + 16 + 25

p(x) = x^2 - 8x + 41

can anyone help me with this answer?

Answers

Answer:

6m-2m+12 and 4(m+3)

Step-by-step explanation:

4(m+12)=4m+48❎

3m-m+12=2m+12❎

6m-2m+12=4m+12✅

4(m+3)=4m+12✅

g(x) = 2x
Find g(g(-3))

Answers

would it be g^2 - 3g ?

At the end of the first day three of the cricketers scored these runs 28, 61 and 39
The man adds them together and the total score is 128
But his friend checks his calculation by using approximation
Show how the friend used approximation to check the calculation

Answers

Answer:

His friend took one from 61 and added it to 39. That made it easy to mentally add 40 and 60 to get 100. Then he mentally added 28 to 100 to get 128.

If you know how to do this please help me.

Answers

Answer:

Undefined or no values (assuming no negative zero)

Step-by-step explanation:

The absolute value of a number (a) keeps/turns it positive. A positive number can never be equal to a negative number.

ill mark brainlist plss help

Answers

Step-by-step explanation:

Perimeter of rectangle = 2(l+b)

= 2(97+17)

= 2(114)

= 228cm

Answer:

P = 228 inches

Step-by-step explanation:

P = 2(l + w)

l = 97 inches

w = 17 inches

P = 2 (97 + 17)

P = 2 x 114

P = 228

Can someone please give me the answer I will mark u brilliant

Answers

The first question is B and the second one is C

Answer:

p = 16.8

[tex] r \geqslant 5.5[/tex]

Step-by-step explanation:

12)

p + 2.1 = 18.9

p = 18.9 - 2.1

p = 16.8

13)

[tex]r \geqslant 5.5[/tex]

45633 seconds en heures minutes et seconds

Answers

Yes. I totally agree with that statement. 10/10

Which of the following equations has a graph in the
xy-plane for which y is always greater than or equal
to -1 ?
A) y = |x| - 2
B) y = x2 - 2
C) y = (x - 2)2
D) y = x3 - 2

Answers

Answer: (x-2)2

Step-by-step explanation:

The required equation is  [tex]y=(x-2)^2[/tex]

The correct answer is an option (C)

What is an equation?

"It is a mathematical statement which consists of equal symbol between two algebraic expressions."

For given question,

We have been given four equations.

We need to find an equation for which y is always greater than or equal

to -1.

Consider,

A. y = ∣x∣ - 2

We know that the minimum value of ∣x∣ is 0.

So, the minimum value of y becomes -2

Hence, this is not a required equation.

B. [tex]y=x^{2} -2[/tex]

We know that the square of any number is always positive.

The minimum value of [tex]x^{2}[/tex] is 0.

So, the minimum value of y becomes −2

Hence, this is not a required equation.

C. [tex]y=(x-2)^2[/tex]

We know that the square of any number is always positive.

The minimum value of y is zero.

This means, the y value of equation  [tex]y=(x-2)^2[/tex] is always greater than -1.

D. [tex]y=x^3-2[/tex]

We know that [tex]x^3[/tex] can go have negative values. This means it may have value that tends to negative infinity.

This means, the y can be less than -1 and this is not a required equation.

Therefore, the required equation is  [tex]y=(x-2)^2[/tex]

The correct answer is an option (C)

Learn more about the equation here:

https://brainly.com/question/13170101

#SPJ2

work out the circumference of this circle

give your answer in terms of pi and state its units
14cm​

Answers

Answer:

43.96

Step-by-step explanation:

Well, the first step is finding out the diameter. And then the basic outline is d x 3.14. So I simply just punched in 14 x 3.14 in my calculator.

Answer:

14π cm

Step-by-step explanation:

Circumference of the circle

= 2πr

= 2π(14/2)

= 14π cm

On a map, the distance of two inches is equal to ten miles. How many
miles does 4 inches represent on the map?
10
20
30
40

Answers

20! hope this helps!

pls help I'll mark the first person brainliest answer all​

Answers

Answer:

4

a. 12

b. 8

c. 30

d. 40

Step-by-step explanation:

each exterior = 360/n

30*n=360

divide both side by 30

Answer is 12

The same apply to others to 4d

so first its 4

a. 12

b. 8

c. 30

d. 40

i will try to explain:

each exterior = 360/n

30*n=360

divide both side by 30

Answer is 12

The same apply to others to 4d

Ecologists wanted to estimate the mean biomass (amount of vegetation) of a certain forested region. The ecologists divided the region into plots measuring 1 square meter each, and they selected a random sample of 9 plots. The mean biomass of the 9 plots was 4.3 kilograms per square meter (kg/m2) and the standard deviation was 1.5 kg/m2 . Assuming all conditions for inference are met, which of the following is a 95 percent confidence interval for the population mean biomass, in kg/m2?
A) 4.3±1.96 (underroot 1.5/3).
B) 4.3±1.96 (1.5/3).
C) 4.3 ± 2.306 (underroot 1.5/9).
D) 4.3±2.3064 (1.5/9).
E) 4.3+2.30/15 (1.5/3).

Answers

Answer:

[tex]4.3 \pm 2.306\frac{1.5}{\sqrt{9}}[/tex], option c

Step-by-step explanation:

We have the standard deviation for the sample, so we use the t-distribution to solve this question.

The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So

df = 9 - 1 = 8

95% confidence interval

Now, we have to find a value of T, which is found looking at the t table, with 8 degrees of freedom(y-axis) and a confidence level of [tex]1 - \frac{1 - 0.95}{2} = 0.975[/tex]. So we have T = 2.306

The margin of error is:

[tex]M = T\frac{s}{\sqrt{n}} = 2.306\frac{1.5}{\sqrt{9}}[/tex]

In which s is the standard deviation of the sample and n is the size of the sample.

Confidence interval:

The confidence interval is the sample mean plus/minus the margin of error. So

[tex]4.3 \pm 2.306\frac{1.5}{\sqrt{9}}[/tex]

The correct answer is given by option c.

Mookie Betts of the Boston Red Sox had the highest batting average for the 2018 Major League Baseball season. His average was 0.352. So, the likelihood of his getting a hit is 0.352 for each time he bats. Assume he has five times at bat tonight in the Red Sox-Yankee game. a. This is an example of what type of probability

Answers

Answer:

Binomial probability, with [tex]n = 5, p = 0.352[/tex]

Step-by-step explanation:

For each time Mookie Betts went to bat, there were only two possible outcomes. Either he got a base-hit, or he did not. The probability of getting a hit on each at-bat is independent of any other at-bat. This 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.

His average was 0.352.

This means that [tex]p = 0.352[/tex]

Assume he has five times at bat tonight in the Red Sox-Yankees game.

This means that [tex]n = 5[/tex]

a. This is an example of what type of probability

Binomial probability, with [tex]n = 5, p = 0.352[/tex]

PEASE HELP DUE IN 5 MINUTES I WILL MARK YOU BRAINLIST



Find the area of a regular hexagon with side length of 3 ft. Round your answer to the nearest tenth
7.8 ft2
11.7 ft2
23.4 ft2
40.5 ft2​

Answers

23.4 ft2

Step-by-step explanation:

jvuctctctcrxrxrxrxrxr

Here is a circle. Points A, B, C, and D are drawn, as
well as Segments AD and BC.
D.
What is the area of the circle, in square units?

Answers

Area of a circle = pi *r^2
A=pi*4^2
A=50.24 square units

Hope it helps

Krish and Aanya gor to a restaurant for dinner. Their meals total $13.75. The tax is 5%

a. How much tax is added to the bill?
b. Aanya and Krish want to leave a 15% tip based on their bill and tax combined. How much should they leave?

Answers

Answer:

A) $6.87

B) $3.09

Step-by-step explanation:

I will mark u brainalist

Answers

Answer:

C

Step-by-step explanation:

The cost of 5 notebooks (5x)

Less than (<)

The cost of 3 notebooks (3x)

Plus a 2 dollar pen (2)

All together: 5x < 3x + 2

Matches with the given expression.

keiko has bought 36pounds of dog food, she feed the dog 3/4 pound of food each meal. how many meals would this last

Answers

Answer:

48 meals

Step-by-step explanation:

36lbs ÷ 3/4lbs = 48

Ryan needs $100 for a new bike. He already has $28 and will make $12 per day working for his grandfather. Write an inequality to find the number of days he must work to make enough money for the bike.

Answers

Answer:

100 ≥ 12x + 28

Step-by-step explanation:

He needs $100 for the new bike but already has the $28 so you also have to add 12x because thats what you need to find. X represents the amount of days he has to work.

Describe what happens to the exponential function when the value of "k" is
positive. *

Answers

Answer:

Step-by-step explanation:It isn’t. There are really 4 different versions of the exponential function. Positive (like the growth of money invested at 5%), negative (like the US debt constantly becoming more negative), positive decay (like the half life of a radioactive element), or negative decay ( pay half your loan amount in year 1, 1/4 in year two, 1/8 in year three, you in theory will never pay your loan completely but the debt is growing closer to zero.

Determine which lines, if any, are parallel? Explain.

PLEASE PLEASE HELP ME ASAP

Answers

Answer:

The 2 on the right because they don't cross and they are straight

Step-by-step explanation:

I’d say the two on the right side, but I’m not sure so don’t take my word for it
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