3 years ago

Solve x2-14x+21=0 by completing the square

1 answer:

4 0

$x^2-14x+21=0\\\\x^2-2x\cdot7+7^2-7^2+21=0\\\\(x-7)^2-49+21=0\\\\(x-7)^2-28=0\\\\(x-7)^2=28\iff x-7=-\sqrt{28}\ \vee\ x-7=\sqrt{28}\\\\x=7-\sqrt{4\cdot7}\ \vee\ x=7+\sqrt{4\cdot7}\\\\x=7-2\sqrt7\ \vee\ x=7+2\sqrt7$

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sweet-ann [11.9K]

First you convert kilograms to pounds,
1 kilogram = 2.205 pounds
next you times the number of pounds per kilogram by the number of kilograms given that need to be turned into pounds.
80 times 2.205 = 176.4
next you subtract to get the answer
176.4 - 135= 41.4
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Given the linear correlation coefficient r and the sample size n, determine the critical values of r and use your

Mila [183]

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<h3>What are the critical values of r?</h3>

Question Parameters

r = -0.868

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df = 5 - 2

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Critical values $r= \pm 0.878$

Generally, there exists no linear correlation between the Critical values

as r=0.878

In conclusion, Critical values: r = +0.487, no significant linear correlation

Read more about Critical values

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Answer:

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