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3 years ago

El exceso de un número sobre 20 es igual a las tres cuartas partes del mismo número. ¿Cuál es el número?

Mathematics

1 answer:

Dennis_Churaev [7]3 years ago

4 0

Answer:

The number is 80

Step-by-step explanation:

The question in English is

The excess of one number over 20 equals three quarters of the same number. What is the number?

Let

x ------> the number

we know that

The linear equation that represent this situation is

$x-20=\frac{3}{4}x$

Solve for x

$x-\frac{3}{4}x=20$

$\frac{1}{4}x=20$

$x=80$

therefore

The number is 80

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A local citizen wants to fence a rectangular community gardenn. The length of the garden should be at least 110ft,and the distan

Arte-miy333 [17]

The question is incorrect
the correct question is
A local citizen wants to fence a rectangular community garden. The length of the garden should be at least 110 ft,and the distance around should be no more than 380 ft. Write a system of inequality that model the possible dimensions of he garden. Graph the system to show all possible solutions

let
x---------------> t<span>he length of the garden
</span>y---------------> the wide of the garden

we know that
x>=110
2x+2y <=380---------------> x+y <= 190

Part A) <span>Write a system of inequality that model the possible dimensions of he garden
</span>
the answer part A) is
x>=110
x+y <= 190

Part B) <span>Graph the system to show all possible solutions

using a graph tool
see the attached figure
the solution is the triangle show in the figure

</span><span>the possible solutions of y (wide) would be between 0 and 80 ft
</span>the possible solutions of x (length) would be between 110 ft and 190 ft

5 0

3 years ago

I’m a bit confused here

alekssr [168]

Y= -x and y= -1/x
Are one-one
y= -x, inverse x= -y
Identify function
hence, inverse of y= -x in y= -x
similarly in the case of y= -1/x
so option (D) I and II, only

7 0

1 year ago

Use your calculator to select the best answer below:

bixtya [17]

Answer:

$-2\sqrt{a}$

Step-by-step explanation:

$\lim_{x \to a} \frac{a-x}{\sqrt{x} -\sqrt{a} } \\ =-\lim_{x \to a} \frac{x-a}{\sqrt{x} -\sqrt{a} } \\=-\lim_{x \to a} \frac{(\sqrt{x} -\sqrt{a})(\sqrt{x} +\sqrt{a})}{\sqrt{x} -\sqrt{a} } \\=- \lim_{x \to a} \sqrt{x} +\sqrt{a}\\=-2\sqrt{a}$

6 0

3 years ago

Many people use scanners to read documents and store them into pdf file. To help determine which brand of scanner to buy, a stud

konstantin123 [22]

The data is missing in the question. The data is provided below :

Document : 1 2 3 4 5 6 7 8

Brand A 17 29 18 14 21 25 22 29

Brand B 21 38 15 19 22 30 31 37

Solution :

State of the hypothesis of the null hypothesis and alternate hypothesis.

Null hypothesis : $h_A = h_B$

Alternate hypothesis : $h_A > h_B$

These hypothesis is a one tailed test. The null hypothesis will get rejected when the mean difference between the sample means is very small.

Significance level = 0.05

Therefore the standard error is : $SE = \sqrt{(\frac{s^2_1}{n_1})+(\frac{s^2_2}{n_2})}$

= 3.602

And the degree of freedom, DF = 14

$t=\frac{(x_1-x_2)-d}{SE}$

= -1.319

Here, $s_1$ = standard deviation of the sample 1

$s_2$ = standard deviation of the sample 2

$n_1$ = size of the sample 1

$n_2$ = size of the sample 2

$x_1$ = mean of the sample 1

$x_2$ = mean of the sample 2

d = the hypothesis difference between the population mean

The observed difference in a sample means t static of -1.32. From t distribution calculator to determine P( $t \leq -1.32$ ) = 0.1042

Since the P value of 0.1042 is greater than significance level o 0.05, we therefore cannot reject the null hypothesis.

But from the test, we have no sufficient evidence that supports that Brand A is better than Brand B.

8 0

3 years ago

Solve the following problems. Remember that all reasoning must be explained, and all steps of math work must be shown!

chubhunter [2.5K]

<h2>Question 1:</h2>

<h3>How to solve Part A</h3>

Since the diagram shows a right triangle and gives out some measurements of the sides, you can use the Pythagorean Theorem ( $a^{2}+b^{2}=c^{2}$ ) to find the length of MP.

<u>Given:</u>

hypotenuse = 7 – because the radius is 7 units and it can be used as the hypotenuse

One side of the triangle = 4 – because the length of PO is 4 units and it can be used as one sides of the triangle

<u>To Solve:</u>

Since we know two values of the triangle, you can use the Pythagorean Theorem ( $a^{2}+b^{2}=c^{2}$ ) to find what the other value is. The variables <em>c</em> and <em>b</em> in the formula are already given, and we need to find what <em>a</em> is to find the length of MP. So, plug the given values of <em>c</em> and <em>b</em> into the formula:

$a^{2}+4^{2}=7^{2}$

Simplify:

$a^{2}+16=49$

Subtract 16 from both sides of equation:

$a^{2}=33$

Do the square root of both sides to isolate the variable <em>a</em>:

$\sqrt{a^{2}}=\sqrt{33}$

Evaluate:

$a=\sqrt{33}$ Which simplifies to $a= 5.744562646....$ and round it to the nearest tenth to finally get $a=5.7$

Answer: The length of MP is 5.7 units

<h3>How to solve Part A</h3>

If you look at the diagram in the question, you can see that the length of MN is twice the length of MP. So multiply the length of MP, which is 5.7, by 2:

5.7 · 2 = 11.4

Answer: The length of MN is 11.4 units

___________________________________________________________

<h2>Question 2:</h2>

<h3>How to solve Part A</h3>

Look at the <u>first image</u> below ↓

<u>Description of the first image:</u>

The first image shows a drawn image of the circle with labeled parts and measurements from the infomation given from the question.

The diameter is 26cm, which means that the radius is 13cm because the radius half of the diameter in a circle. The very top line is the surface of the water where it’s filled and it has a length of 20cm. Side <em>b</em> of the triangle is 10cm becuase it’s half the length of the the surface of the water bowl. The hypotenuse (side <em>c</em>) is 13cm because it’s the length of the radius. And side <em>a </em>is what what we need to find because it’s the distance between the surface of the water and the center of the bowl. But after when you find the length of side <em>a</em>, you need to add the length of the radius (which is 13cm) to the length of side <em>a</em> because that’s the rest of the length/depth of the water that’s filled in the bowl. The length of the radius is included with the depth of the water.

<u>Total information given:</u>

⇒ radius = 13cm – because the radius is half of the diameter, and the diameter has a length of 26cm

⇒ length of the surface where the water’s filled = 20cm

⇒ hypotenuse (side <em>c</em>) = 13cm – because it’s the length of the radius

⇒ side <em>b</em> = 10cm – because it’s half the length of the surface where the water’s filled

<u>To Solve</u>

Since there is a right triangle shown in the image, you can use the Pythagorean Theorem ( $a^{2}+b^{2}=c^{2}$ ) to find the missing length of side <em>a</em>. Plug the given values of <em>c</em> and <em>b</em> into the formula:

$a^{2}+10^{2}=13^{2}$

Simplify:

$a^{2}+100=169$

Subtract 100 from both sides of the equation:

$a^{2}=69$

Do the square root of both sides to isolate the variable <em>a</em>:

$\sqrt{a^{2}}=\sqrt{69}$

Evaluate:

$a=\sqrt{69}$ Which simplifies to $a= 8.30662386....$ and round it to the nearest tenth to finally get $a$ ≈ $8.3$

This means that 8.3 is just the length of side <em>a</em>, which is the length between the surface of where the water’s filled and the center of the circle. But, now you need to add 13 to 8.3 to find the total depth of the water because the length of the radius is included with the depth of the water.

So,

13 + 8.3 = 21.3

Answer: The depth of the water is approximately 21.3 cm

<h3>How to solve Part B (is in the image below)</h3>

<em />

<em>Sorry for the very, VERY long explanation and the long solving process, but I really, really hope you understand and that this helps with your question! </em>:)

4 0

3 years ago