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2 years ago

The area of a rectangle is x² + 2x -15. If its length is x + 2 units, what is its width?

Mathematics

1 answer:

Luda [366]2 years ago

3 0

Length of the rectangle is 8 units

Step-by-step explanation:

Step 1: Find the length, let width be x.

Area of the rectangle = 48 units

Length = x + 2

⇒ Area = Length × Breadth

48 = x (x + 2)

48 = x² + 2x

x² + 2x - 48 = 0

x² + 8x - 6x + 48 = 0 (Product Sum rule to factorise)

x(x + 8) - 6(x + 8) = 0

(x - 6)(x + 8) = 0

⇒ x = 6, -8 (negative value is neglected)

∴ x = 6

x + 2 = 8

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kakasveta [241]

Answer:

600

Step-by-step explanation:

Because the tens digit is less than 5, round down to 600

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1 year ago

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What is the cross section shown below?

goldenfox [79]

<h3>Answer: Choice A) circle</h3>

Explanation:

Imagine that white rectangle as a blade that cuts the cylinder as the diagram shows. If you pull the top cylinder off and examine the bottom of that upper piece, then you'll see a circle forms. It's congruent to the circular face of the original cylinder. This is because the cutting plane is parallel to both base faces of the cylinder. Any sort of tilt will make an ellipse form. Keep in mind that any circle is an ellipse, but not vice versa.

Another example of a cross section: cut an orange along its center and notice that a circle (more or less) forms showing the inner part of the orange.

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3 years ago

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What’s the linear equation for (1,21)(2,33)(3,45)(4,57)

nalin [4]

The linear equation representing the above said pair of points is "y=12x+9"

Step-by-step explanation:

The given set of points are

x Y

1 21

2 33

3 45

4 57

For finding the linear equation for the given sets of value

We must know the generic form of a linear equation is y=m*x + c

m= slope of the line where y= Δy/Δx

Δy= change in y value

Δx= change in x value

Thus slope ”m” = 33-21/2-1 = 12

we put slope “m” in the equation which becomes y=12x+c

Now we put any of the set value in the equation

33= 12*2+c ∴ c=9

Hence required linear equation is y=12x+9

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2 years ago

A public bus company official claims that the mean waiting time for bus number 14 during peak hours is less than 10 minutes. Kar

ch4aika [34]

Answer:

We conclude that the mean waiting time is less than 10 minutes.

Step-by-step explanation:

We are given that a public bus company official claims that the mean waiting time for bus number 14 during peak hours is less than 10 minutes.

Karen took bus number 14 during peak hours on 18 different occasions. Her mean waiting time was 7.8 minutes with a standard deviation of 2.5 minutes.

Let $\mu$ = mean waiting time for bus number 14.

So, Null Hypothesis, $H_0$ : $\mu \geq$ 10 minutes {means that the mean waiting time is more than or equal to 10 minutes}

Alternate Hypothesis, $H_A$ : $\mu$ < 10 minutes {means that the mean waiting time is less than 10 minutes}

The test statistics that would be used here One-sample t test statistics as we don't know about the population standard deviation;

T.S. = $\frac{\bar X-\mu}{\frac{s}{\sqrt{n} } }$ ~ $t_n_-_1$

where, $\bar X$ = sample mean waiting time = 7.8 minutes

s = sample standard deviation = 2.5 minutes

n = sample of different occasions = 18

So, test statistics = $\frac{7.8-10}{\frac{2.5}{\sqrt{18} } }$ ~ $t_1_7$

= -3.734

The value of t test statistics is -3.734.

Now, at 0.01 significance level the t table gives critical value of -2.567 for left-tailed test.

Since our test statistic is less than the critical value of t as -3.734 < -2.567, so we have sufficient evidence to reject our null hypothesis as it will fall in the rejection region due to which we reject our null hypothesis.

Therefore, we conclude that the mean waiting time is less than 10 minutes.

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3 years ago

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natta225 [31]

Answer:C

Step-by-step explanation:

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2 years ago