I dont understand this...<br>#8 solve for j

What is the solution to 2x2+x+2=0

nikitadnepr [17]

$2x^2 + x + 2 = 0$

$x = \dfrac{1}{8}(-1 \pm \sqrt{1- 4(2)(2)})= \dfrac{-1 \pm \sqrt{-15}}{8}$

$x = \dfrac{-1 \pm i\sqrt{15}}{8}$

Two solutions, complex conjugates.

8 0

3 years ago

Read 2 more answers

Three gallons of paint are used to paint 16 wooden signs.how much paint did each sign use. Between what two whole numbers does t

marysya [2.9K]

Given Question: Three gallons of paint are used to paint 16 wooden signsNow, let's solve how much paint did each sign use and between what two whole numbers does the answer lie?=> 3 gallons of paints : 16 wooden sign.First let's identify how many gallons of paints will it needs to be able to paint a single wooden signs.=> 3 gallons / 16 wooden signs = 0.19 gallons of paint per wooden sign.For the second question, i don't know what you mean. <span>
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5 0

4 years ago

63% of US adults opposed to taxes on junk food and soda. You randomly select 10 US adults. Find the probability that the number

WARRIOR [948]

Answer:

a) 0.0008 = 0.08% probability that the number of adults who oppose special tax on junk food and soda is exactly one.

b) 0.9644 = 96.44% probability that the number of adults who oppose special tax on junk food and soda is at least four.

c) 0.7795 = 77.95% probability that the number of adults who oppose special tax on junk food and soda is less than eight.

Step-by-step explanation:

For each adult, there are only two possible outcomes. Either they are opposed to taxes on junk food and soda, or they are not. Each adult is independent of other adults, which means that the binomial probability distribution is used to solve the 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.

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

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

$C_{n,x} = \frac{n!}{x!(n-x)!}$

And p is the probability of X happening.

63% of US adults opposed to taxes on junk food and soda.

This means that $p = 0.63$

You randomly select 10 US adults.

This means that $n = 10$

(a) exactly one

This is $P(X = 1)$ . So

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 1) = C_{10,1}.(0.63)^{1}.(0.37)^{9} = 0.0008$

0.0008 = 0.08% probability that the number of adults who oppose special tax on junk food and soda is exactly one.

(b) at least four

This is

$P(X \geq 4) = 1 - P(X < 4)$

In which

$P(X < 4) = P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3)$

So

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 0) = C_{10,0}.(0.63)^{0}.(0.37)^{10} \approx 0$

$P(X = 1) = C_{10,1}.(0.63)^{1}.(0.37)^{9} = 0.0008$

$P(X = 2) = C_{10,2}.(0.63)^{2}.(0.37)^{8} = 0.0063$

$P(X = 3) = C_{10,3}.(0.63)^{3}.(0.37)^{7} = 0.0285$

$P(X < 4) = P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3) = 0 + 0.0008 + 0.0063 + 0.0285 = 0.0356$

$P(X \geq 4) = 1 - P(X < 4) = 1 - 0.0356 = 0.9644$

0.9644 = 96.44% probability that the number of adults who oppose special tax on junk food and soda is at least four.

(c) less than eight

This is

$P(X < 8) = 1 - P(X \geq 8)$

In which

$P(X \geq 8) = P(X = 8) + P(X = 9) + P(X = 10)$

In which

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 8) = C_{10,8}.(0.63)^{8}.(0.37)^{2} = 0.1529$

$P(X = 9) = C_{10,1}.(0.63)^{9}.(0.37)^{1} = 0.0578$

$P(X = 10) = C_{10,2}.(0.63)^{10}.(0.37)^{0} = 0.0098$

$P(X \geq 8) = P(X = 8) + P(X = 9) + P(X = 10) = 0.1529 + 0.0578 + 0.0098 = 0.2205$

$P(X < 8) = 1 - P(X \geq 8) = 1 - 0.2205 = 0.7795$

0.7795 = 77.95% probability that the number of adults who oppose special tax on junk food and soda is less than eight.

5 0

3 years ago

Find the sum of the finite geometric sequence

lions [1.4K]

Answer:

45

Step-by-step explanation:

Use the geometric sum formula for in infinite sum. 20 terms of this basic formula is close enough The 20th term is 8.6 * 10^-10 which means this goes out to a number with 9 zeros after the decimal and before the 8.

Put another way, the tenth number of this series is the only one affected.

When you use a spreadsheet, it seems to know that the answer is 3/2 as the solution to the sum.

Solution.

Sum = a / (1 - r)

a = 1

r = 1/3

Sum = 1 / (1 - 1/3)

Sum = 1 // 2/3

sum = 3/2

Now you can worry about the 30.

30 * sum(1/3)^n = 30* 3/2 = 45

If there is something you want more information on, leave a note.

6 0

4 years ago

The width of the rectangle

Nikolay [14]

Answer:

84cm^2

Step-by-step explanation:

P=2l+2w

We are given,

P=40cm

l=2w+2

Plug these into the first formula and solve for the dimensions,

length and width, of the rectangle:

40=2(2w+2)+2w Simplify

40=4w+4+2w

40=6w+4

36=6w

6=w OR the width is 6cm, therefore,

the length is

l=2(6)+2

l=14cm

To calculate the area of a rectangle, A=lw,

plug the length,14cm, and the width, 6cm, into this formula

A=(14)(6)

A=84cm2 OR the area of the rectangle is 84cm^2

7 0

3 years ago

I dont understand this...#8 solve for j