All categories

3 years ago

Does anyone know this?!??

Mathematics

1 answer:

kondor19780726 [428]3 years ago

6 0

Indeed!

This is a quadratic equation, and there are several ways to factor this. I will try to explain the way I do it and try to make sense of it.

2x^2-x-15 - Original Equation

Now set up an X(as I cannot draw very well in brainly it will look bad)

1 -3

\ /

/ \

2 5

This might all look very confusing so let me explain it.

First on the left side of the x, 1*2=2 which is the coefficient of the x^2 term.

The right side, -3*5=-15 which is the constant term.

What I did in the graph thing was to find 2 such pairs that line up in the graph in a way that the opposite corners multiplied and added together would = -1.

Such as the way I lined up the graph.

1*5(one of the diagonals) + 2*-3(the second diagonals)=5-6=-1 the coefficient of the middle term.

As long as you find 2 such pairs you got the answer, just write it from left it right then top to bottom.

The first ( ) would be (1x-3), the second ( ) would be (2x+5)

Now we can always switch the ( ) as in this problem we can write the answer as (x-3)(2x+5) or switch it around as (2x+5)(x-3).

Therefore the answer A is the correct answer.

**<u>If you have any questions about my explanation, simply ask me in the comment section and I will come answer. (I know my explanation here isn't the most clear so you probably will ask questions and please don't just put the answer in and be done with it, actually try to understand my explanation it will help with further questions like this.)</u>

You might be interested in

A collection of dimes and quarters has a total value of $3.95. If there are 20 coins in the collection, how many are there of ea

tamaranim1 [39]

Answer:

13 quarters and 7 dimes

Step-by-step explanation:

3 dollars is 12 quarters. add 7 dimes gets you 75 cents then add 1 quarter gets you 20 coins and 3.95

4 0

3 years ago

Every time Liliana bakes a batch of brownies, she uses 34 cup of chocolate. If she has 128 cup(s) of chocolate remaining, how ma

tester [92]

Answer:

= 3 batches

Step-by-step explanation:

128÷34=3.7647

She can only make three full batches. There would only be 76% of the amount needed left to make a fourth batch.

8 0

3 years ago

A square brick is 11 inches on each side. What is the area of one face of the break?

musickatia [10]

All sides of a square are the same so if the length of one is is 11 inches, then all of the sides are 11 inches.
To work out the area of a square you multiply the length and the width.
In this case the sum would be: 11 x 11
The answer to that is 121.
So overall, the answer would be 121 inches.

8 0

3 years ago

A taxi ride costs p40.00 for the first 500 meters and each additional 300 meters or a fraction there of adds p3.50 to the fare.u

Zarrin [17]

The function which represents the taxi fare in terms of distance d in meter is f(d) = 3.50 × $\frac{d-500}{300}$ + 40 .

According to the question,

For first 500 meters cost is 40.00 and For each additional 300 meters cost is 3.50 .

Let, the total distance of taxi ride = d meters

Now, representing the equation of taxi fare in terms of distance when distance is less than 500

taxi fare = 3.50 × $\frac{d-500}{300}$ + 40

∴ f(d) = 3.50 × $\frac{d-500}{300}$ + 40

To know more about functions refer below link: brainly.com/question/12431044

#SPJ4

8 0

2 years ago

Geologist has collected 10 specimens of basaltic rock and 10th specimens of granite. The geologist instructs a laboratory assist

olya-2409 [2.1K]

Answer:

$p(5)=0.00136$

(a) $p(x)=\frac{(10Cx)*((10)C(15-x))}{20C10}$

(b) $p(10)+p(5)=0.00272$

Step-by-step explanation:

If we have N elements with k elements that we consider success and N-k elements that we consider fail, and we take a sample of n elements, the probability that there are x successes in the sample follows a hypergeometric distribution, so it is calculated as:

$p(x)=\frac{(kCx)*((N-k)C(n-x))}{NCn}$

In this case, N is equal to 20, k is equal to 10 specimens of granite rock, N-k is equal to 10 specimens of basaltic rock and n is 15. So, the probability that there are x specimens of granite rock in the sample or the pmf of the number of granite specimens selected for analysis is:

$p(x)=\frac{(10Cx)*((10)C(15-x))}{20C10}$

Now, the probability of getting exactly 5 granite specimens selected for analysis is:

$p(5)=\frac{(10C5)*((10)C(15-5))}{20C10}=0.00136$

On the other hand, the probability that all specimens of one of the two types of rock are selected for analysis is the probability to select 10 granite specimens or 10 basaltic specimens. Where the probability to take 10 basaltic specimens is equal to the probability to take 5 granite specimens.

Then, the probability that all specimens of one of the two types of rock are selected for analysis is:

$p(10)+p(5)=\frac{(10C10)*((10)C(15-10))}{20C10}+\frac{(10C5)*((10)C(15-5))}{20C10}\\p(10)+p(5)=0.00136+0.00136=0.00272$

For the hypergeometric distribution, the mean E(x) and standard deviation S(x) are:

$E(x)=\frac{nk}{N}=\frac{15*10}{20}=7.5\\S(x)=\sqrt{\frac{nk}{N}*(1-\frac{k}{N})*(\frac{N-n}{N-1})}\\S(x)=\sqrt{\frac{15*10}{20}*(1-\frac{10}{20})*(\frac{20-15}{20-1})}=0.9934$

Then, the number of granite specimens within 1 standard deviation of its mean value is:

E(x) - S(x) ≤ mean ≤ E(x) + S(x)

7.5-0.9934 ≤ mean ≤ 7.5+0.9934

6.5066 ≤ mean ≤ 8.4934

7 ≤ mean ≤ 8

Finally, the probability that the number of granite specimens selected for analysis is within 1 standard deviation of its mean value is:

$p(7)+p(8)=\frac{(10C7)*((10)C(15-7))}{20C10}+\frac{(10C8)*((10)C(15-8))}{20C10}\\p(10)+p(5)=0.0292+0.0292=0.0584$

8 0

4 years ago