If y varies inversely as x, and y = 18 when x = 2, how do you find y when x = 4?

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If y varies inversely as x, and y = 18 when x = 2, how do you find y when x = 4?

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Answer 1 · 2018-05-21T13:42:47

y = 9

Explanation:

If x is doubled then y is cut in half, since they are inversely related

$\frac{18}{2} = 9$ $18/2 =9$

Answer 2 · 2018-05-21T13:49:57

$y = 9$ $y=9$

Explanation:

$the initial statement is y \propto \frac{1}{x}$ $"the initial statement is "yprop1/x$

$to convert to an equation multiply by k the constant$ $"to convert to an equation multiply by k the constant"$
$of variation$ $"of variation"$

$\Rightarrow y = k \times \frac{1}{x} = \frac{k}{x}$ $rArry=kxx1/x=k/x$

$to find k use the given condition$ $"to find k use the given condition"$

$y = 18 when x = 2$ $y=18" when "x=2$

$y = \frac{k}{x} \Rightarrow k = y x = 18 \times 2 = 36$ $y=k/xrArrk=yx=18xx2=36$

$"equation is " color(red)(bar(ul(|color(white)(2/2)color(black)(y=36/x)color(white)(2/2)|)))$

$"when "x=4" then"$

$y=36/4=9$

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If y varies inversely as x, and y = 18 when x = 2, how do you find y when x = 4?

2 Answers

Explanation:

Explanation:

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