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3 years ago

Can someone help please i don't understand

Mathematics

1 answer:

mel-nik [20]3 years ago

3 0

Answer:

x= -3/11

Step-by-step explanation:

Use cross multiplication:

5(x+1)= -1(6x-2)

Simplify:

5x+5= -6x+2

Subtract 5 from both sides:

5x= -6x-3

Add 6x to both sides:

11x= -3

Divide both sides by 11:

x= -3/11

Hope this helps ^-^

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ZanzabumX [31]

Answer: idk tbh

Step-by-step explanation:

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3 years ago

katie bought 4 sweaters that each cost the same amount and 1 skirt that costs 20$. The items she bought cost a total of 160$ bef

Alika [10]

Hello, in order to solve this you first need to take $20 subtracted from 160 that leaves you with 140 next because she bought 4 sweaters you need to divide your remaining cash spent by 4 to get a total of $35 a sweater.

I hope this is what you were looking for, have a great day!

8 0

3 years ago

A chemist has a 40% alcohol solution and a 25% alcohol solution. How much of each should he mix together to get 50 liters of a 3

ludmilkaskok [199]

Answer:

33 1/3 L of the 40% solution, 16 2/3 L of the 25% solution

Step-by-step explanation:

Set up two equations...

Let x represent the number of Liters of the 40% solution

Let y represent the number of Liters of the 25% solution

We need 50 liters total, so

x + y = 50

and we need the 50 L to be 35% solution, so

0.4x = 0.25y = 0.35(50)

Solve the first equation for one variable...

x = 50 - y (subtract y from both sides in equation 1)

Now substitute that value into the second equation...

0.4(50 - y) + 0.25y = 17.5 (x becomes 50 - y, 0.35(50) = 17.5)

Now solve for y...

20 - 0.4y + 0.25y = 17.5

-0.15y = -2.5

y = 16.66666667

y = 16 2/3 L

So we need to plug that into the first equation to find 'x'

x + 16 2/3 = 50

x = 50 - 16 2/3

x = 33 1/3

3 0

3 years ago

Read 2 more answers

Which of the following describes the translation of the graph of y = x2 to obtain the graph of y = -x2 - 3?

Ray Of Light [21]

Answer:

reflections across the x axis and a shift down 3 units

Step-by-step explanation:

y = x^2

The negative sign means it is a reflection across the x axis y = −f(x)

y = -x^2

The subtraction of 3 means we are shifting down 3 units

y = -x^2 -3

5 0

3 years ago

The speeds of vehicles traveling on a highway are normally distributed with an unkown population mean and standard deviation. A

Maksim231197 [3]

Answer:

The 90% confidence interval would be given by (60.09;69.91)

We are 90% confident that the true mean for the speeds of vehicles traveling on a highway is between 60.09 and 69.91 miles per hour.

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".

$\bar X =65$ represent the sample mean for the sample

$\mu$ population mean (variable of interest)

s=9 represent the sample standard deviation

n=11 represent the sample size

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

$df=n-1=11-1=10$

Since the Confidence is 0.90 or 90%, the value of $\alpha=0.1$ and $\alpha/2 =0.05$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-T.INV(0.05,10)".And we see that $t_{\alpha/2}=1.81$

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

$65-1.81\frac{9}{\sqrt{11}}=60.09$

$65+1.81\frac{9}{\sqrt{11}}=69.91$

So on this case the 90% confidence interval would be given by (60.09;69.91)

We are 90% confident that the true mean for the speeds of vehicles traveling on a highway is between 60.09 and 69.91 miles per hour.

3 0

3 years ago

Can someone help please i don't understand ​

Can someone help please i don't understand