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3 years ago

Someone please help me

Mathematics

1 answer:

Dovator [93]3 years ago

5 0

<h3>Answer: B) 2</h3>

=========================================================

Explanation:

Take away the four white small squares on the left side. To balance things out, you have to add 4 black squares to the right side.

Also, take away the two white long rectangles from the right side. To balance this out, you have to add 2 gray long rectangles to the left side.

You should have:

5 gray rectangles, and no squares (of any color) on the left side
10 black squares, no long rectangles (of any color), on the right side

From here you'll group up the 10 black squares so that you'll have 2 black squares per gray rectangle.

This means the solution is 2.

-------------------------------------

If you're curious about the algebraic way to solve, then you could do this:

3x-4 = -2x+6

3x+2x = 6+4

5x = 10

x = 10/5

x = 2

This method doesn't require us to use the visual model.

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Which is the best first step when solving the following system of equations? 5 c + 4 d = 10. 3 c + 2 d = 16. Multiply the first

Virty [35]

Answer:

5c+4d=10

3c+2d=16

8c+6c=26

8 0

2 years ago

Choose the graph that represents the following system of inequalities:

Licemer1 [7]

Answer:

FIRST.

64 square inches matches to a cross section parallel to the base of a right rectangle prism that is 3 inches long, 7 inches wide, and 11 inches tall

This is shown in the first figure below. A right rectangular prism where every edge connecting its base and the opposite face makes right angles with both faces. Since the tall is the side that measures 11 inches, then the base is formed by 3 inches long and 7 inches wide. Therefore, the area of this shape can be found as the area of a rectangle, which is: 21 in squared.

SECOND.

64 square inches matches to a cross section parallel to the base of a cube whose edges are 8 inches long.

This is shown in the second figure below. A cube is a prism whose sides all have the same length and in this case is 8 inches. We name cross section is to the slice that cuts through a solid. If the cross section is parallel to the base of a cube, then it forms a square with length . Therefore, the area of this shape can be found as the area of a square, which is: 64 in squared.

Third.

7 square inches matches to a cross section passing through the diagonal of opposite faces of a cube with edges that are 7 inches long and a diagonal that is approximately 10 inches

This is shown in the third figure below. As you can see, the cross section passes through the diagonals of the base and the top of the cube that are two opposite faces. This form a rectangle having sides where:

So: 70 in squared

FOURTH.

300 square inches matches to a cross section perpendicular to the base and passing through the diagonals of the base and opposite face of a right rectangular prism that is 24 inches wide, 7 inches long, and 12 inches tall and measures 25 inches along the diagonal of the base.

This is shown in the fourth figure below. The cross section passes through the diagonals of the base and the top of the right rectangular prism. They are opposite to each other, so the shape of the cross section is a rectangle whose sides are where:

So: 300 in squared.

Step-by-step explanation:

6 0

3 years ago

Find two numbers, if … b Their sum is −7 and their difference is 14

Delicious77 [7]

Answer:

x=0

y=-21/7

Step-by-step explanation:

Let the two unknown be x and y

x+y=-7...(1)

x-y=14...(2)

From (1) make x the subject of formula

x=-7-y...(3)

Substitute (3) into (2)

-7-y-y=14

-7-2y=14

Add 7 to both sides

-2y=21

Add both sides by-2

y=-21/2

Substitute the value of y into (3)

x=-7-(-21/2)

x=-7+21/3

Lcm

x=-21+21/3

x=0/3

x=0

4 0

3 years ago

PLEASE HELLPPP**attachments provided

Luden [163]

Answer:

A. 2x(x+1)(x-6); 0, -1, 6

Step-by-step explanation:

The zeros are the values of x that make the factors zero. That is, for binomial factors, they are the opposite of the constant in the binomial factor. For example, the factor (x+1) will be zero when x = -1, so that -1+1 = 0.

This observation eliminates choices B and C.

The product of binomial factors looks like this:

(x +a)(x +b) = x² +(a+b)x +ab . . . . . x-coefficient is (a+b)

Once 2x is factored from the given polynomial, the resulting quadratic is ...

x^2 -5x -6

This means the sum of the constants in the binomial terms must be -5. That will only be the case for choice A.

3 0

2 years ago

A quality control expert at LIFE batteries wants to test their new batteries. The design engineer claims they have a variance of

iris [78.8K]

Answer:

The probability that the mean battery life would be greater than 533.2 minutes (in a sample of 75 batteries) is $\\ P(z>0.48) = P(x>533.2) = 0.3156$

Step-by-step explanation:

The main thing we have to take into account in this question is that we are about to find the probability of a sample mean. The distribution for sample means follows a normal distribution with mean $\\ \mu$ and standard deviation $\\ \frac{\sigma}{\sqrt{n}}$ . Mathematically

$\\ \overline{x} \sim N(\mu, \frac{\sigma}{\sqrt{n}})$

For values of the sample $\\ n \ge 30$ , no matter the distribution the data come from.

And the variable z follows a standard normal distribution, and, as we can remember, this distribution has a mean = 0 and a standard deviation = 1. Mathematically

$\\ z = \frac{\overline{x} - \mu}{\frac{\sigma}{\sqrt{n}}}$ [1]

That is

$\\ z \sim N(0, 1)$

We have a variance of 3364. That is, a standard deviation of

$\\ \sigma^2 = 3364; \sigma = \sqrt{3364} = 58$

The population mean is

$\\ \mu = 530$

The sample size is $\\ n = 75$

The sample mean is $\\ \overline{x} = 533.2$

With all this information, we can solve the question

The probability that the mean battery life would be greater than 533.2 minutes

Using equation [1]

$\\ z = \frac{\overline{x} - \mu}{\frac{\sigma}{\sqrt{n}}}$

$\\ z = \frac{533.2 - 530}{\frac{58}{\sqrt{75}}}$

$\\ z = \frac{3.2}{\frac{58}{8.66025}}$

$\\ z = \frac{3.2}{6.69726}$

$\\ z = 0.47780$

With this value of z we can consult a cumulative standard normal table (or use some statistic program) to find the cumulative probability for z (and remember that this variable follows a standard normal distribution).

Most standard normal tables have values for z for only two decimals, so we can round the previous value for z as z = 0.48.

Then

$\\ P(z$

However, in the question we are asked for $\\ P(z>0.48) = P(x>533.2)$ . As well as all normal distributions, the standard normal distribution is symmetrical around the mean, and we have

$\\ P(z>0.48) = 1 - P(z$

Thus

$\\ P(z>0.48) = 1 - 0.68439$

$\\ P(z>0.48) = 0.31561$

Rounding to four decimal places, we have

$\\ P(z>0.48) = 0.3156$

So, the probability that the mean battery life would be greater than 533.2 minutes is (in a sample of 75 batteries) $\\ P(z>0.48) = P(x>533.2) = 0.3156$ .

5 0

3 years ago