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3 years ago

Solve the system useing elimination 4x+8y=16 6x-8y=4

Mathematics

1 answer:

nydimaria [60]3 years ago

6 0

Answer:

x=2 and y=1

Step-by-step explanation:

Add the two equations to remove "y" and solve for x:

4x+8y=16

6x-8y=4

________

10x=20

x=2

Plug x=2 into one of the original equations to get the value of "y":

4x+8y=16

4(2)+8y=16

8+8y=16

8y=8

y=1

Therefore, x=2 and y=1

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The graph of y=x^3 is transformed as shown in the graph below. Which equation represents the transformed function?

omeli [17]

Answer:

y = (-x)^3 - 4

Step-by-step explanation:

Ok, for the function:

y = x^3

When x = 0, we have:

y = 0^3 = 0

So the original graph passes through the point (0, 0)

If we look at the given graph, we can see that the y-intercept (the value of y when x = 0) is:

y = -4

So, this is the graph of y = x^3 moved down 4 units.

You can also see that the graph goes downward as x increases (and up as x decreases) while for the function:

y = x^3

as x increases, we should see that y also increases.

Then we have a reflection across the x-axis.

Ok, now let's describe a vertical shift.

For a general function f(x), a vertical shift of N units is written as:

g(x) = f(x) + N

if N is positive, the shift is upwards

if N is negative, the shift is downwards.

And for a function f(x), a reflection across the x-axis is written as:

g(x) = - f(x)

Here we first apply the reflection across the x-axis, so we get:

g(x) = -f(x)

now we apply the shift 4 units downwards

g(x) = - f(x) - 4

replacing f(x) by our function, x^3

we get:

g(x) = -x^3 - 4

And because of the odd power, we can write:

-x^3 = (-x)^3

Then the function is:

g(x) = (-x)^3 - 4

The correct option is the last one.

y = (-x)^3 - 4

3 0

3 years ago

After the first term in a sequence, the ratio of each term to the preceding term is r. If the first term is a, what is the third

irinina [24]

Answer:

The 3rd term is

$ar^2$

Step-by-step explanation:

From the given information, the first term of the sequence is

$a_1=a$

The common ratio of the sequence is

$r$

The explicit formula for a geometric sequence is :

$a_n=a_1(r^{n-1})$

To find the third term, we put n=3 to get:

$a_n=a(r^{3-1})$

This simplifies to:

$a_3=ar^2$

7 0

3 years ago

The state education commission wants to estimate the fraction of tenth grade students that have reading skills at or below the e

marusya05 [52]

Answer:

The estimation for the proportion of tenth graders reading at or below the eighth grade level is given by:

$\hat p =\frac{955-812}{955}= 0.150$

$0.150 - 1.64 \sqrt{\frac{0.150(1-0.150)}{955}}=0.131$

$0.150 + 1.64 \sqrt{\frac{0.150(1-0.150)}{955}}=0.169$

And the 90% confidence interval would be given (0.131;0.169).

Step-by-step explanation:

We have the following info given:

$n= 955$ represent the sampel size slected

$x = 812$ number of students who read above the eighth grade level

The estimation for the proportion of tenth graders reading at or below the eighth grade level is given by:

$\hat p =\frac{955-812}{955}= 0.150$

The confidence interval for the proportion would be given by this formula

$\hat p \pm z_{\alpha/2} \sqrt{\frac{\hat p(1-\hat p)}{n}}$

For the 90% confidence interval the significance is $\alpha=1-0.9=0.1$ and $\alpha/2=0.05$ , with that value we can find the quantile required for the interval in the normal standard distribution and we got.

$z_{\alpha/2}=1.64$

And replacing into the confidence interval formula we got:

$0.150 - 1.64 \sqrt{\frac{0.150(1-0.150)}{955}}=0.131$

$0.150 + 1.64 \sqrt{\frac{0.150(1-0.150)}{955}}=0.169$

And the 90% confidence interval would be given (0.131;0.169).

8 0

3 years ago

Help pls I need help pls

-Dominant- [34]

What are you supposed to do?

3 0

3 years ago

Lorena is designing a rectangular patio in her garden. She has enough tiles to cover 324 square feet. She wants the length of th

IceJOKER [234]

Using the area of a rectangle, it is found that her patio should have a width of 12 feet and a length of 27 feet.

<h3>What is the area of a rectangle?</h3>

The area of a rectangle of length l and width w is given by:

A = lw.

In this problem:

She has enough tiles to cover 324 square feet, hence A = 324.

She wants the length of the patio to be 15 feet longer than the width, hence l = 15 + w.

Thus:

324 = w(15 + w)

w^2 + 15w - 324 = 0

w = -27 or w = 12.

We take the positive value, hence l = 15 + w = 15 + 12 = 27 feet.

The dimensions should be a width of 12 feet and a length of 27 feet.

You can learn more about the area of a rectangle at brainly.com/question/10489198

7 0

2 years ago