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3 years ago

Can someone help me?It's urgent and thank you!

Mathematics

1 answer:

allochka39001 [22]3 years ago

3 0

Answer:

the first option

Step-by-step explanation:

because x^3 is exponential while ab^2 is linear

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1.) You are one of five people who have been hired to mow the lawn at the local college. Each week, the dimensions of the plot y

iren [92.7K]

Answer:

1a) Length = 7x + 3 & Width = 4x - 2

1b) Area = $28x^2 -2x -6$

1c) Area = 2774 sq. m

2. $(x-4)(y+7)$

Step-by-step explanation:

1a)

The length given as words is "3 more than 7 times x"

The width given as words is "4 times x minus 2"

The expression for length would be 7x + 3

The expression for width would be 4x - 2

1b)

The area is length * width

Since we already know the algebraic expressions for length and width from part (a) above, we use the formula:

Area = (7x+3)(4x-2) = 28x^2 -14x + 12x - 6 = 28x^2 -2x -6

Area = $28x^2 -2x -6$

1c)

Given x = 10, we put this into the area expression we found in (b) above.Let's see:

$28x^2 -2x -6\\=28(10)^2 -2(10) -6\\=2774$

Area = 2774 sq. m

We can group the first two terms and next two terms and write up:

$xy-4y+7x-28\\(xy-4y)+(7x-28)\\y(x-4)+7(x-4)\\(x-4)(y+7)$

That's the factored form.

8 0

3 years ago

Read 2 more answers

Write 368% as a mixed number.

Allushta [10]

Answer:

$3\frac{17}{25}$

Step-by-step explanation:

368%

convert to a fraction

$\frac{368}{100}$

divide top and bottom by 2

$\frac{184}{50}$

divide top and bottom by 2

$\frac{92}{25}$

92/25 = 3 remainder 17

$3\frac{17}{25}$

8 0

3 years ago

Find two number closest to 5000 that are divisible by 36,21,and 12

Pavlova-9 [17]

1,008 hope this helps

7 0

3 years ago

6x-1=x+3 Proszę o pomoc!!!

timama [110]

Answer:

The answer is 4/5

Step-by-step explanation:

#Hope it helps uh.....

5 0

2 years ago

Read 2 more answers

A sample of eight workers in a clothing manufacturing company gave the following figures for the amount of time(in minutes) need

lilavasa [31]

Answer:

$10.108 < \mu < 13.892$

Step-by-step explanation:

1) Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

$\bar X$ represent the sample mean for the sample

$\mu$ population mean (variable of interest)

s represent the sample standard deviation

n represent the sample size

We have the following distribution for the random variable:

$X \sim N(\mu , \sigma=0.45)$

And by the central theorem we know that the distribution for the sample mean is given by:

$\bar X \sim N(\mu, \frac{\sigma}{\sqrt{n}})$

2) Confidence interval

The confidence interval for the mean is given by the following formula:

$\bar X \pm t_{\alpha/2}\frac{s}{\sqrt{n}}$ (1)

In order to calculate the mean and the sample deviation we can use the following formulas:

$\bar X= \sum_{i=1}^n \frac{x_i}{n}$ (2)

$s=\sqrt{\frac{\sum_{i=1}^n (x_i-\bar X)}{n-1}}$ (3)

The mean calculated for this case is $\bar X=12$

The sample deviation calculated $s=2.268$

In order to calculate the critical value $t_{\alpha/2}$ we need to find first the degrees of freedom, given by:

$df=n-1=8-1=7$

Since the Confidence is 0.95 or 95%, the value of $\alpha=0.05$ and $\alpha/2 =0.025$ , and we can use excel, a calculator or a tabel to find the critical value. The excel command would be: "=-T.INV(0.025,7)".And we see that $t_{\alpha/2}=2.36$

Now we have everything in order to replace into formula (1):

$12-2.36\frac{2.268}{\sqrt{8}}=10.108$

$12+2.36\frac{2.268}{\sqrt{8}}=13.892$

So on this case the 95% confidence interval would be given by (10.108;13.892)

$10.108 < \mu < 13.892$

7 0

3 years ago