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3 years ago

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Autumn starts with 1 milligram of a radioactive substance. The amount of the substance decreases by 50% each week for a number o

f weeks, w. She writes the expression (1−0.5)w to find the amount of radioactive substance remaining after w weeks.

1 answer:

krok68 [10]3 years ago

3 0

Answer:

Andrea's Expression: (1 - 0.2)^w

w: number of weeks

0.2: percent decrease

1 - 0.2: decay factor for each week

I got Eric's Expression wrong :(

Click to let others know, how helpful is itAndrea's Expression: (1 - 0.2)^w

w: number of weeks

0.2: percent decrease

1 - 0.2: decay factor for each week

I got Eric's Expression wrong :(

Click to let others know, how helpful is itAndrea's Expression: (1 - 0.2)^w

w: number of weeks

0.2: percent decrease

1 - 0.2: decay factor for each week

I got Eric's Expression wrong :(

Click to let others know, how helpful is itAndrea's Expression: (1 - 0.2)^w

w: number of weeks

0.2: percent decrease

1 - 0.2: decay factor for each week

I got Eric's Expression wrong :(

Click to let others know, how helpful is it

Step-by-step explanation:

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iren2701 [21]

I would say A. 16.5 %

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Here is a rectangle ABCD.

lana66690 [7]

Answer:

32%

Step-by-step explanation:

Area of rectangle ABCD = 20 * 30 = 600 Sq cm

After increasing the length and width of the rectangle by 20% and 10% respectively.

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New width = 20 + 10% of 20 = 20 + 2 = 22 cm

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Increase in area = 792 - 600 = 192 Sq cm

Percentage increase in area

= (192/600) *100

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3 years ago

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The sides of the rectangle are in the ratio of 4:7. If its length is 31.5 in., find the width, the perimeter, and the area of th

AveGali [126]

Let $\ell$ the length and $w$ the width. By the ratio of the sides:

$\dfrac{w}{\ell}=\dfrac{4}{7}\Longrightarrow \dfrac{w}{31.5}=\dfrac{4}{7}\Longrightarrow w=\dfrac{4\cdot31.5}{7}\Longrightarrow \boxed{w=18~in.}$

Now, we'll find the perimeter p. We'll use the formula below:

$p=2(\ell+w)\\\\
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The area of a rectangle is $S=w\cdot\ell$ . Then:

$S=w\cdot\ell\\\\
S=18\cdot31.5\\\\
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3 years ago

Read 2 more answers

The LCM of 42, 63, and 84 is

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3| 42 , 63 , 84

7| 14 , 21 , 28

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2 years ago

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worty [1.4K]

9514 1404 393

Answer:

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Step-by-step explanation:

There is really no substitute for a good probability table, app, or calculator. Any of these, or a spreadsheet, will tell you the value of Z is about 1.25027.

__

The attachment shows a spreadsheet computation.

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2 years ago