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3 years ago

If y varies inversely with x and y =5 when x=20 find x when y = -4

Mathematics

1 answer:

sweet-ann [11.9K]3 years ago

7 0

Answer:

x=-25

Step-by-step explanation:

Inverse variation

xy =k

We know x and y

20*5 =k

100 =k

So the formula is

x y = 100

We know y = -4

x (-4) = 100

Divide each side by -4

-4x/-4 = 100/-4

x = -25

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The area of a rectangle is 56 square yards. Its length is 2 yards more than three times its width. Find its dimensions

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2 years ago

An agency is studying the income of store managers in the retail industry. A random sample of 25 managers reveals a sample mean

aalyn [17]

Answer:

The Confidence Interval = ($44,745.55 , $46,094.45)

Step-by-step explanation:

The formula for Confidence Interval =

Confidence Interval = Mean ± z × Standard deviation/√n

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Mean = $45,420

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= 1.645

Confidence Interval = $45,420 ± 1.645 × $2,050/√25

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Confidence Interval =

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2 years ago

Please help, will give 5 stars

Alexus [3.1K]

Function 1
rate of change = (80-100)/(2-1) = -20
y = -20x + 120

function 2
y = -18x + 120
rate of change = -18

answer
function 2 shows a greater rate of change

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3 years ago

Consider the function given by the graph. What are these values?

Natalija [7]

As you see in the picture, there are two lines that could maybe represent two linear functions. However, this is not true because of the solid point and the hollow point. This is an inequality equation that has points of discontinuity.

Points of discontinuity are breaks in the graph that are a result of an undefined point when the f(x) is substituted with a point of x that is not part of the solution. So, technically, the graph is made from one rational expression.

So, when it says f(-2), this is the y-value at x=-2. That means f(-2)=2, f(0)=3 and f(4)=-1. Specifically, there are two points at x=0, but we take the solid point only.

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3 years ago

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If y varies inversely with x and y =5 when x=20 find x when y = -4​

If y varies inversely with x and y =5 when x=20 find x when y = -4