All categories

3 years ago

Assume that y varies inversely with x. if y=7 when x=-2, find y when x=7

Mathematics

1 answer:

melisa1 [442]3 years ago

8 0

Answer:

y=-2

Step-by-step explanation:

The formula for inverse variation is

xy =k

if y=7 when x=-2, we can substitute these numbers in to find k

(-2)(7) =k

-14 =k

The equation becomes

xy = -14

Let x =7

7y = -14

Divide each side by 7

7y/7 = -14/7

y = -2

You might be interested in

Guess the value of the limit (correct to six decimal places). (if an answer does not exist, enter dne.) lim hâ0 (4 + h)5 â 1024

kupik [55]

$\displaystyle\lim_{h\to0}\frac{(4+h)^5-1024}h=\lim_{h\to0}\frac{(4+h)^5-4^5}h$

Recall the definition of the derivative of a function $f(x)$ at a point $x=c$ :

$f'(c)=\displaystyle\lim_{h\to 0}\frac{f(c+h)-f(c)}h$

We can then see that $f(c)=c^5$ , and by the power rule we have $f'(c)=5c^4$ . Then replacing $c=4$ , we arrive at

$\displaystyle\lim_{h\to0}\frac{(4+h)^5-4^5}h=5\times4^4=1280$

Alternatively, we could have expanded the binomial, giving

$\dfrac{(4+h)^5-4^5}h=\dfrac{(4^5+5\times4^4h+10\times4^3h^2+10\times4^2h^3+5\times4h^4+h^5)-4^5}h$
$=\dfrac{1280h+640h^2+160h^3+20h^4+h^5}h$
$=1280+640h+160h^2+20h^3+h^4$

and so as $h\to0$ we're left with 1280, as expected.

4 0

3 years ago

Write which goes in each box plz help ASAP!!!

jeka94

Answer:

Command Economy:

China during the Cold War.

North Korea during the Cold War.

Market Economy:

Japan during the Cold War.

South Korea during the Cold War.

Taiwan during the Cold War.

<u>Mongolia during the Cold War</u><u>:</u>

As when I was taking History, Mongolia was not really a topic during the World War, but I believe that Mongolia is a market economy due to it's fairly bad relations with the USSR.

3 0

3 years ago

Read 2 more answers

If 2x-4(3-x)=18, then x=_____? Can someone please help me with this problem

denis-greek [22]

Answer:

Answer is below

Step-by-step explanation:

Simplify both sides of the equation.

$2x-4(3-x)=18\\2x+(-4)(3)+(-4)(-x)=18$

DIstribute

$2x+-12+4x=18\\(2x+4x)+(-12)=18$

CLT

$6x+-12=18\\6x-12=18$

Add 12 to both sides.

$6x-12+12=18+12\\6x=30$

Divide both sides by 6.

$\frac{6x}{6} =\frac{30}{6}\\ x=5$

7 0

3 years ago

In a computer game, when choosing a character there are 5 choices for hair style, 3 choices for eye color, and 7 choices for out

Irina-Kira [14]

Hey there!

If there are 5 choices for a hairstyle, that means that there are 5 options per 1 eye color. This totals out to 15 options (3 × 5) total for eye color and hairstyle combinations.

For each of those combinations, there are an additional 7 options for an outfit. That means that there is a total of 105 options (7 × 15) available to choose from.

Hope this helped you out! :-)

3 0

3 years ago

20 points, Thanks to whoever helps! (and brainliest)

damaskus [11]

Answer:

To find a 20 percent tip quickly, first find 10%, and then multiply it by 2.

Step-by-step explanation:

To find 10%, move the decimal 1 place to the left. So 10% of 53.82 is 5.382. Let's round that to 5.4 to simplify. Multiply it by 2 to get to 20% which is 10.8 and round to the nearest dollar to make $11.

4 0

3 years ago