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3 years ago

50 points, question is down below.

Mathematics

2 answers:

maks197457 [2]3 years ago

6 0

$\dfrac{\frac{3}{x-1}-4}{2-\frac{2}{x-1}}=\left(\dfrac{3}{x-1}-\dfrac{4(x-1)}{x-1}\right):\left(\dfrac{2(x-1)}{x-1}-\dfrac{2}{x-1}\right)\\\\=\dfrac{3-4x+4}{x-1}\cdot\dfrac{2x-2-2}{x-1}=\dfrac{-4x+7}{x-1}\cdot\dfrac{x-1}{2x-4}\\\\=\dfrac{-4x+7}{1}\cdot\dfrac{1}{2(x-2)}=\dfrac{-4x+7}{2(x-2)}$

kozerog [31]3 years ago

4 0

Answer:

the second one

Step-by-step explanation:

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Melissa has 350 in her savings account. she decides that she will put the same amount of money each month into her account.Her g

Ray Of Light [21]

C = 350+xm
mc=350+x
m = (350+x)/c

7 0

3 years ago

1.<br> Find the least common multiple.<br> 20 and 12

musickatia [10]

Answer:

answer 60

Step-by-step explanation:

The LCM(12, 20) = 60.

4 0

3 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 $n = 20$

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

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

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

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

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

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

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

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

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 $n = 22$

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

The closest integer to 16.5 is 17.

7 0

3 years ago

15/4 in to equal mixed number

Temka [501]

9514 1404 393

Answer:

3 3/4

Step-by-step explanation:

$\dfrac{15}{4}=\dfrac{12+3}{4}=\dfrac{12}{4}+\dfrac{3}{4}\\\\=3+\dfrac{3}{4}=\boxed{3\dfrac{3}{4}}$

The integer part of the mixed number is the quotient when the numerator is divided by the denominator. The remainder from that division is the numerator of the fraction.

15/4 = 15 ÷ 4 = 3 r 3 = 3 3/4

5 0

3 years ago

Explain how to add +20 and -36. GIVING BRAINLIEST TO WHOEVER GIVE THE RIGHT ANSWER!!! :)

Sonja [21]

Answer:

-16

Step-by-step explanation:

In this problem, we are adding a negative integer and a positive integer. From this, we already know that the sum will be negative. (- plus + = -)

Since 20 is positive, you can remove the plus sign so your equation looks like

20 - 36

Next, subtract to get -16

~theLocoCoco

6 0

3 years ago

Read 2 more answers