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2 years ago

(x + 3)^2 - 4x^2 Factorise using the difference of two squares

Mathematics

1 answer:

AlladinOne [14]2 years ago

8 0

Answer:

3(x + 1)(3 - x).

Step-by-step explanation:

(x + 3)^2 - 4x^2

Using the identity a^2 - b^2 = (a - b)(a + b), we have

(x + 3 - 2x)(x + 3 + 2x)

= (-x + 3)(3x + 3)

= 3(x + 1)(3 - x)

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In math, the word dilate means to

Fynjy0 [20]

Answer: it means to make larger or smaller.

Step-by-step explanation:

it means to make larger or smaller.

7 0

2 years ago

Read 2 more answers

Assume that there is a 4% rate of disk drive failure in a year. a. If all your computer data is stored on a hard disk drive wit

kap26 [50]

Answer:

a) 99.84% probability that during a year, you can avoid catastrophe with at least one working drive

b) 99.999744% probability that during a year, you can avoid catastrophe with at least one working drive

Step-by-step explanation:

For each disk drive, there are only two possible outcomes. Either it works, or it does not. The disks 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.

4% rate of disk drive failure in a year.

This means that 96% work correctly, $p = 0.96$

a. If all your computer data is stored on a hard disk drive with a copy stored on a second hard disk drive, what is the probability that during a year, you can avoid catastrophe with at least one working drive?

This is $P(X \ geq 1)$ when $n = 2$

We know that either none of the disks work, or at least one does. The sum of the probabilities of these events is decimal 1. So

$P(X = 0) + P(X \geq 1) = 1$

We want $P(X \geq 1)$ . So

$P(X \geq 1) = 1 - P(X = 0)$

In which

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

$P(X = 0) = C_{2,0}.(0.96)^{0}.(0.04)^{2} = 0.0016$

$P(X \geq 1) = 1 - P(X = 0) = 1 - 0.0016 = 0.9984$

99.84% probability that during a year, you can avoid catastrophe with at least one working drive

b. If copies of all your computer data are stored on four independent hard disk drives, what is the probability that during a year, you can avoid catastrophe with at least one working drive?

This is $P(X \ geq 1)$ when $n = 4$

We know that either none of the disks work, or at least one does. The sum of the probabilities of these events is decimal 1. So

$P(X = 0) + P(X \geq 1) = 1$

We want $P(X \geq 1)$ . So

$P(X \geq 1) = 1 - P(X = 0)$

In which

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

$P(X = 0) = C_{4,0}.(0.96)^{0}.(0.04)^{4} = 0.00000256$

$P(X \geq 1) = 1 - P(X = 0) = 1 - 0.00000256 = 0.99999744$

99.999744% probability that during a year, you can avoid catastrophe with at least one working drive

7 0

3 years ago

The equation y = kx represents a proportional relationship between x and y, where k is the constant of proportionality. For a mo

kvasek [131]

Answer:

Hello!!!

In this specific case the constant of proportionality is s (speed).

Step-by-step explanation:

The constant of proportionality stay "constant" (as the name suggests) in a certain case.

meaning, the speed itself remains constant at any given distance or time.

You can use the constant of proportionality and either distance or time to find the missing varliable since it remains constant.

you can also switch up the formula:

d=st

t=d/s

s=d/t

i really hope this helps!!!!!

3 0

2 years ago

The area of the kite is 48cm squared what are the lengths of the diagonals

Anika [276]

We see from the attached, that kite area = product of the diagonals / 2
The diagonals could be 12 by 8 or
6 by 16 or
3 by 32, etc
It cannot be narrowed down any further.

5 0

3 years ago

Find the coordinates of the centroid of triangle RST. SHOW YOUR WORK so I can see if the answer makes sense (no links)

zimovet [89]

Note the coordinates of each point: R(-4, 5), S(5, 1), T(2, -3).

The centroid is the point whose coordinates are the average of the coordinates of R, S, and T.

<em>x</em>-coordinate: (-4 + 5 + 2)/3 = 3/3 = 1

<em>y</em>-coordinate: (5 + 1 - 3)/3 = 3/3 = 1

So the centroid is (1, 1).

3 0

2 years ago