Ask question

Ask question

All categories

3241004551 [841]

4 years ago

9

Factor: x^2 - 81

alt=" {x}^{2} - 81" align="absmiddle" class="latex-formula">

1 answer:

beks73 [17]4 years ago

7 0

(x - 9)(x + 9) is your answer. This is called a difference of two squares.

You might be interested in

The ratio of frogs to swans is 2:6. What is the ratio of swans to the total number of animals.

SSSSS [86.1K]

Answer:

6:8

Step-by-step explanation:

2:6 to find the total number of animals add the numbers 2+6=8

since there are 6 swans

6:8

3 0

3 years ago

It snowed 20 inches in 10 days in Canada. At what unit rate did the snow fall?

tatiyna

It falled at a unit rate of 2. Divide 20 by 10 . Mark me the brainlyest

6 0

3 years ago

Read 2 more answers

A particular concentration of a chemical found in polluted water has been found to be lethal to 40% of the crayfish that are exp

Jet001 [13]

Answer:

a) $P(X=13)=(24C13)(0.4)^{13} (1-0.4)^{24-13}=0.0608$

$P(X=17)=(24C17)(0.4)^{17} (1-0.4)^{24-17}=0.0017$

$P(X=13 U X=17) = 0.0608+0.0017=0.0624$

b) $P(X \geq 17)=0.000427$

c) $P(X \geq 16)= 1-0.000427=0.9996$

d) $E(X)= np = 22*0.4=8.8$

e) $Var(X) = np(1-p)= 22*0.4*(1-0,4)=5.28$

Step-by-step explanation:

1) Previous concepts

The binomial distribution is a "DISCRETE probability distribution that summarizes the probability that a value will take one of two independent values under a given set of parameters. The assumptions for the binomial distribution are that there is only one outcome for each trial, each trial has the same probability of success, and each trial is mutually exclusive, or independent of each other".

2) Solution to the problem

Let X the random variable of interest, on this case we now that:

$X \sim Binom(n=24, p=0.4)$

The probability mass function for the Binomial distribution is given as:

$P(X)=(nCx)(p)^x (1-p)^{n-x}$

Where (nCx) means combinatory and it's given by this formula:

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

3) Part a

$P(X=13)=(22C13)(0.4)^{13} (1-0.4)^{22-13}=0.0336$

$P(X=17)=(22C17)(0.4)^{17} (1-0.4)^{22-17}=0.00035$

$P(X=13 U X=17) = 0.0336+0.00035=0.0340$

4) Part b

$P(X \geq 17)=P(X=17)+P(X=18)+P(X=19)+P(X=20)+P(X=21)+P(X=22)$

$P(X=17)=(22C17)(0.4)^{17} (1-0.4)^{22-17}=0.00035$

$P(X=18)=(22C18)(0.4)^{18} (1-0.4)^{22-18}=0.0000651$

$P(X=19)=(22C19)(0.4)^{19} (1-0.4)^{22-19}=0.00000914$

$P(X=20)=(22C20)(0.4)^{20} (1-0.4)^{22-20}=0.000000914$

$P(X=21)=(22C21)(0.4)^{21} (1-0.4)^{22-21}=5.81x10^{-8}$

$P(X=22)=(22C22)(0.4)^{22} (1-0.4)^{22-22}=1.76x10^{-9}$

$P(X \geq 17)=0.000427$

5) Part c

$P(X \leq 16)=1-P(X>16)=1-P(X\geq 17) = 1-[P(X=17)+P(X=18)+P(X=19)+P(X=20)+P(X=21)+P(X=22)]$

$P(X \geq 16)= 1-0.000427=0.9996$

6) Part d

The expected value is:

$E(X)= np = 22*0.4=8.8$

7) Part e

The variance is given by:

$Var(X) = np(1-p)= 22*0.4*(1-0,4)=5.28$

3 0

3 years ago

Find the Perimeter of the figure below, composed of a parallelogram and one

Neporo4naja [7]

The perimeter of the figure to the nearest tenth is 44.6 units

<h3>Perimeter of a figure?</h3>

The perimeter of a figure is the sum of the whole sides.

Therefore,

A parallelogram has opposite sides equal to each other.

Therefore, the perimeter of the figure is as follows;

The figure combines a parallelogram and a semi circle.

Therefore,

perimeter of the figure = 4 + 14 + 14 + πr

perimeter of the figure = 32 + 3.14 × 4

perimeter of the figure = 32 + 12.56

perimeter of the figure = 44.56

perimeter of the figure ≈ 44.6 units

learn more on perimeter here: brainly.com/question/22532312

#SPJ1

7 0

2 years ago

The triangles below are similar.<br> Pls help me

siniylev [52]

Answer: I think the answer would be nine. Hear me out

Step-by-step explanation: The left triangle has the angles 5 and 4, so the right answer for the other side would be the angles 8 and x=9.

8 0

3 years ago

Read 2 more answers