What is the rest of the expression?
Answer:
7x - y = -7
Step-by-step explanation:
Hope this helps!
Answer:
x = -8
Step-by-step explanation:
5x - 4 + 7x = 5(2x - 4)
12x - 4 = 10x - 20
<u> +20 +20</u>
12x + 16 = 10x
<u>-12x -12x</u>
16 = -2x
divide by -2
x = -8
65 - 17 = 48 books delivered
as 8 per box , 48/8 = 6 boxes delivered
now she has97 books, 97- 17 = 80
as 8 per box, 80/8 = 10 boxes in total,
<span>therefore 4 bonus boxes of comicbooks were delivered</span>
Using the binomial distribution, there is a 0.6328 = 63.28% probability that she wins at most 1 prize.
For each box, there are only two possible outcomes, either it has a prize, or it does not. The probability of a box having a prize is independent of any other box, hence, the binomial distribution is used to solve this question.
Binomial probability distribution
The parameters are:
- x is the number of successes.
- n is the number of trials.
- p is the probability of a success on a single trial.
In this problem:
- She buys 5 boxes, hence
![n = 5](https://tex.z-dn.net/?f=n%20%3D%205)
- 1 in 4 boxes has a prize, hence
![p = \frac{1}{4} = 0.25](https://tex.z-dn.net/?f=p%20%3D%20%5Cfrac%7B1%7D%7B4%7D%20%3D%200.25)
The probability is:
![P(X \leq 1) = P(X = 0) + P(X = 1)](https://tex.z-dn.net/?f=P%28X%20%5Cleq%201%29%20%3D%20P%28X%20%3D%200%29%20%2B%20P%28X%20%3D%201%29)
Hence:
![P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}](https://tex.z-dn.net/?f=P%28X%20%3D%20x%29%20%3D%20C_%7Bn%2Cx%7D.p%5E%7Bx%7D.%281-p%29%5E%7Bn-x%7D)
![P(X = 0) = C_{5,0}.(0.25)^{0}.(0.75)^{5} = 0.2373](https://tex.z-dn.net/?f=P%28X%20%3D%200%29%20%3D%20C_%7B5%2C0%7D.%280.25%29%5E%7B0%7D.%280.75%29%5E%7B5%7D%20%3D%200.2373)
![P(X = 1) = C_{5,1}.(0.25)^{1}.(0.75)^{4} = 0.3955](https://tex.z-dn.net/?f=P%28X%20%3D%201%29%20%3D%20C_%7B5%2C1%7D.%280.25%29%5E%7B1%7D.%280.75%29%5E%7B4%7D%20%3D%200.3955)
Then
![P(X \leq 1) = P(X = 0) + P(X = 1) = 0.2373 + 0.3955 = 0.6328](https://tex.z-dn.net/?f=P%28X%20%5Cleq%201%29%20%3D%20P%28X%20%3D%200%29%20%2B%20P%28X%20%3D%201%29%20%3D%200.2373%20%2B%200.3955%20%3D%200.6328)
0.6328 = 63.28% probability that she wins at most 1 prize.
A similar problem is given at brainly.com/question/24863377