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3 years ago

Factorise X2 + 5x - 66?

Mathematics

1 answer:

masha68 [24]3 years ago

4 0

Step-by-step explanation:

Two factors that have a sum of 5 and a product of -66: 11 and -6.

x² + 5x - 66

= (x + 11)(x - 6).

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Choose the correct graph of the given system of equations. y + 2x = −1 3y − x = 4 graph of two lines that intersect at the point

ELEN [110]

The system of equations has one solution (-1, 1)

<h3>Graph of system of linear equations </h3>

From the question, we are to graph the given system of equations.

The given system of equation is

y + 2x = −1

3y − x = 4

The graph of the given system of equations is shown below.

From the graph, we can observe that the solution to the given system of equation is given by two lines that intersect at the point (-1, 1).

Hence, the system of equations has one solution (-1, 1)

Learn more on Graph of linear equations here: brainly.com/question/14323743

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7 0

1 year ago

-Ready Understand On Earth Day, 40 people volunteert are high-school students. The coordi in high school. ). Write a fraction to

Elden [556K]

Answer:

1/40

Step-by-step explanation:

4 0

3 years ago

A simple random sample of items resulted in a sample mean of . The population standard deviation is . a. Compute the confidence

Varvara68 [4.7K]

Answer:

(a): The 95% confidence interval is (46.4, 53.6)

(b): The 95% confidence interval is (47.9, 52.1)

(c): Larger sample gives a smaller margin of error.

Step-by-step explanation:

Given

$n = 30$ -- sample size

$\bar x = 50$ -- sample mean

$\sigma = 10$ --- sample standard deviation

Solving (a): The confidence interval of the population mean

Calculate the standard error

$\sigma_x = \frac{\sigma}{\sqrt n}$

$\sigma_x = \frac{10}{\sqrt {30}}$

$\sigma_x = \frac{10}{5.478}$

$\sigma_x = 1.825$

The 95% confidence interval for the z value is:

$z = 1.960$

Calculate margin of error (E)

$E = z * \sigma_x$

$E = 1.960 * 1.825$

$E = 3.577$

The confidence bound is:

$Lower = \bar x - E$

$Lower = 50 - 3.577$

$Lower = 46.423$

$Lower = 46.4$ --- approximated

$Upper = \bar x + E$

$Upper = 50 + 3.577$

$Upper = 53.577$

$Upper = 53.6$ --- approximated

<em>So, the 95% confidence interval is (46.4, 53.6)</em>

Solving (b): The confidence interval of the population mean if mean = 90

First, calculate the standard error of the mean

$\sigma_x = \frac{\sigma}{\sqrt n}$

$\sigma_x = \frac{10}{\sqrt {90}}$

$\sigma_x = \frac{10}{9.49}$

$\sigma_x = 1.054$

The 95% confidence interval for the z value is:

$z = 1.960$

Calculate margin of error (E)

$E = z * \sigma_x$

$E = 1.960 * 1.054$

$E = 2.06584$

The confidence bound is:

$Lower = \bar x - E$

$Lower = 50 - 2.06584$

$Lower = 47.93416$

$Lower = 47.9$ --- approximated

$Upper = \bar x + E$

$Upper = 50 + 2.06584$

$Upper = 52.06584$

$Upper = 52.1$ --- approximated

<em>So, the 95% confidence interval is (47.9, 52.1)</em>

Solving (c): Effect of larger sample size on margin of error

In (a), we have:

$n = 30$ $E = 3.577$

In (b), we have:

$n = 90$ $E = 2.06584$

<em>Notice that the margin of error decreases when the sample size increases.</em>

4 0

3 years ago

Write an equation for a parabola in which the set of all points in the plane are equidistant from the focus and line F(-6,0); x=

Bogdan [553]

Step-by-step explanation:

Since we have a vertical directrix, the equation of the parabola is

$(y - k) {}^{2} = 4p(x - h)$

Where p is the distance from the vertex to the directrix.

or the distance from the vertex to the focus.

Since we have a sideways parabola, let use the point for the directrix is (-6,0). So let find the midpoint of (-6,0) and (6,0). That would be our vertex.

$\frac{ - 6 + 6)}{2} = 0$