Help fast please!!! <br><br> 6x + 4 = 2x

3) Solve these problems that have more than one answer.

MaRussiya [10]

Answer:

225

Step-by-step explanation:

Mary = 3x (3 times Carey)

Carey = x

Barry = x/2 (Because Carey read twice as many as Barry, it means he read half the amount Carey did)

3x + x + x/2 = 405

4x + x/2 = 405

8x/2 + x/2 (treat these as fractions) = 405

9x/2 = 405

9x = 810 (cross multiply)

x = 90

Mary = 3(90) 270

Carey = 90

Barry = 90/2 45

Mary - Barry

270 - 45 = 225

Hope this helps! :)

5 0

2 years ago

Read 2 more answers

A teacher pays $39 for 10 books.What is the unit price of each book?

zheka24 [161]

To find the cost of each book, you need to divide the money spent on all of the books by the number of books.

$39 / 10 = $3.90 per book

8 0

3 years ago

Read 2 more answers

How do you do this question it is kinda difficult to understand

Dafna1 [17]

Speed = slope of the line = 20 / 0.5 = 40 km / hr

Second part will be a line with downward slope from the end of the horizontal line Slop = 20 / 1/3 (=60 km/h) So it will pass through the 65 on horizontal axis.

4 0

2 years ago

The probability that your call to a service line is answered in less than 30 seconds is 0.75. Assume that your calls are indepen

vfiekz [6]

Answer:

a) 0.2581

b) 0.4148

c) 17

Step-by-step explanation:

For each call, there are only two possible outcomes. Either they are answered in less than 30 seconds. Or they are not. The probabilities for each call are independent. So we use the binomial probability distribution 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.

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

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.

In this problem we have that:

$p = 0.75$

a. If you call 12 times, what is the probability that exactly 9 of your calls are answered within 30 seconds? Round your answer to four decimal places (e.g. 98.7654).

This is $P(X = 9)$ when $n = 12$ . So

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

$P(X = 9) = C_{12,9}.(0.75)^{9}.(0.25)^{3} = 0.2581$

b. If you call 20 times, what is the probability that at least 16 calls are answered in less than 30 seconds? Round your answer to four decimal places (e.g. 98.7654).

This is $P(X \geq 16)$ when $n = 20$

So

$P(X \geq 16) = P(X = 16) + P(X = 17) + P(X = 18) + P(X = 19) + P(X = 20)$

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

$P(X = 16) = C_{20,16}.(0.75)^{16}.(0.25)^{4} = 0.1897$

$P(X = 17) = C_{20,17}.(0.75)^{17}.(0.25)^{3} = 0.1339$

$P(X = 18) = C_{20,18}.(0.75)^{18}.(0.25)^{2} = 0.0669$

$P(X = 19) = C_{20,19}.(0.75)^{19}.(0.25)^{1} = 0.0211$

$P(X = 20) = C_{20,20}.(0.75)^{20}.(0.25)^{0} = 0.0032$

So

$P(X \geq 16) = P(X = 16) + P(X = 17) + P(X = 18) + P(X = 19) + P(X = 20) = 0.1897 + 0.1339 + 0.0669 + 0.0211 + 0.0032 = 0.4148$

c. If you call 22 times, what is the mean number of calls that are answered in less than 30 seconds? Round your answer to the nearest integer.

The expected value of the binomial distribution is:

$E(X) = np$

In this question, we have $n = 22$

So

$E(X) = 22*0.75 = 16.5$

The closest integer to 16.5 is 17.

7 0

2 years ago

5sin²α+3cos²α / 3sin²α-5cos²α = <br> if tgα=√2

fiasKO [112]

Tgα = tan(α) = sqrt(2)/1 = opposite/ adjacent
opposite = sqrt(2)
adjacent = 1
hypotenuse = sqrt(opposite^2 + adjacent^2)
= sqrt(sqrt(2)^2 + 1^2) = sqrt(3)

sin(α) = opposite/hypotenuse
= sqrt(2)/sqrt(3)

cos(α) = adjacent/hypotenuse
= 1/sqrt(3)

now we can calculate the value of
5sin²α+3cos²α / 3sin²α-5cos²α
... do the math

8 0

3 years ago

Help fast please!!! 6x + 4 = 2x - 12