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3 years ago

Which is the best FIRST STEP when solving the following system of equations?

Mathematics

2 answers:

Degger [83]3 years ago

7 0

Answer:

Multiply the second equation by -2

Step-by-step explanation:

Multiplying equation (II) by -2 makes it easy to continue the equation by elimination method.

the second equation becomes 3c -4d = 32.

Such that it becomes:

5c + 4d = 10... (I)

-6c -4d = -32... (III)

adding equation (1) and (III)

-c = -22

c = 22.

Hope its clear!?

SSSSS [86.1K]3 years ago

4 0

Answer:multiply the first questions by -2

Step-by-step explanation:

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Suppose 52% of the population has a college degree. If a random sample of size 563563 is selected, what is the probability that

amm1812

Answer:

The value is $P(| \^ p - p| < 0.05 ) = 0.9822$

Step-by-step explanation:

From the question we are told that

The population proportion is $p = 0.52$

The sample size is n = 563

Generally the population mean of the sampling distribution is mathematically represented as

$\mu_{x} = p = 0.52$

Generally the standard deviation of the sampling distribution is mathematically evaluated as

$\sigma = \sqrt{\frac{ p(1- p)}{n} }$

=> $\sigma = \sqrt{\frac{ 0.52 (1- 0.52 )}{563} }$

=> $\sigma = 0.02106$

Generally the probability that the proportion of persons with a college degree will differ from the population proportion by less than 5% is mathematically represented as

$P(| \^ p - p| < 0.05 ) = P( - (0.05 - 0.52 ) < \^ p < (0.05 + 0.52 ))$

Here $\^ p$ is the sample proportion of persons with a college degree.

$P( - (0.05 - 0.52 ) < \^ p < (0.05 + 0.52 )) = P(\frac{[[0.05 -0.52]]- 0.52}{0.02106} < \frac{[\^p - p] - p}{\sigma } < \frac{[[0.05 -0.52]] + 0.52}{0.02106} )$

Here

$\frac{[\^p - p] - p}{\sigma } = Z (The\ standardized \ value \ of\ (\^ p - p))$

=> $P( - (0.05 - 0.52 ) < \^ p < (0.05 + 0.52 )) = P[\frac{-0.47 - 0.52}{0.02106 } < Z < \frac{-0.47 + 0.52}{0.02106 }]$

=> $P( - (0.05 - 0.52 ) < \^ p < (0.05 + 0.52 )) = P[ -2.37 < Z < 2.37 ]$

=> $P( - (0.05 - 0.52 ) < \^ p < (0.05 + 0.52 )) = P(Z < 2.37 ) - P(Z < -2.37 )$

From the z-table the probability of (Z < 2.37 ) and (Z < -2.37 ) is

$P(Z < 2.37 ) = 0.9911$

and

$P(Z < - 2.37 ) = 0.0089$

=> $P( - (0.05 - 0.52 ) < \^ p < (0.05 + 0.52 )) =0.9911-0.0089$

=> $P( - (0.05 - 0.52 ) < \^ p < (0.05 + 0.52 )) = 0.9822$

=> $P(| \^ p - p| < 0.05 ) = 0.9822$

3 0

3 years ago

Please please please help me with this assignment :)

Shtirlitz [24]

Answer:

$45.63

Step-by-step explanation:

$50,145 cm^{3} * 2.6 g/cm^3 = 130,377 g\\130,377 g = 130.377 kg\\130.377 kg * $0.35/kg = $45.63\\$

or all together

50,145 cm³ * 2.6 g/cm³ * 0.35/kg = $45.63

6 0

3 years ago

What's a polygon with 5 sides

SVETLANKA909090 [29]

A polygon with 5 sides is known as a Pentagon

5 0

3 years ago

Read 2 more answers

If the data is spread out evenly, the measure of the center that is best to use is the what.

miss Akunina [59]

That would be the mean.

3 0

4 years ago

Read 2 more answers

Solve the equation. show all work<br><br> 18^(r-10)=93

Elina [12.6K]

Recall the logarithm rules :

a^y = x is the same as log_a x = y

In this case,

a = 18
y = r - 10
x = 93

So,

18^ (r-10) = 93

is the same as

log_18 93 = r - 10

Solve for r to get :

10 + log_18 93 = r

3 0

3 years ago