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Marizza181 [45]
3 years ago
7

8x-5y=21 simultaneous linear equation2x+9y=-5

Mathematics
1 answer:
olya-2409 [2.1K]3 years ago
8 0

Answer:

x=2 and y=-1

Step-by-step explanation:

If two equations are given, we can solve one of the equation in terms of single variable and put it in the other equation which will further give the value of x and y.

For the given equations:

8x-5y=21              Equation:1

2x+9y=-5             Equation:2

Solving equation multiply equation 2 with 4 on both the sides

8x+36y=-20        Equation 3

Subtracting Equation:3 from Equation:1

8x-5y-(8x+36y)=21-(-20)\\8x-5y-8x-36y=21+20\\-41y=41\\y=-1

Putting value of 'y' in Equation:2 which will give the value of x

2x+9y=-5\\2x+9(-1)=-5\\2x-9=-5\\2x=4\\x=2

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5 0
3 years ago
The number of hours that a nine month old baby sleeps at night are normally distributed with a population standard deviation of
natita [175]

Answer:

The margin of error is of 0.7123 hours.

Step-by-step explanation:

We have that to find our \alpha level, that is the subtraction of 1 by the confidence interval divided by 2. So:

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Now, we have to find z in the Ztable as such z has a pvalue of 1-\alpha.

So it is z with a pvalue of 1-0.05 = 0.95, so z = 1.645

Now, find the margin of error M as such

M = z*\frac{\sigma}{\sqrt{n}}

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3 0
3 years ago
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Answer:

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Step-by-step explanation:

We are given that

Number of data value=2105

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Average=\frac{sum\;of\;data}{total\;number\;of\;data\;values}

Using the formula

Average=\frac{1008.08}{2105}

Average=0.47\approx 0.5

Hence, the average=0.5

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