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3 years ago

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What is the sum of the first five terms of a geometric series with a1 =20 and r =1/4?

1 answer:

drek231 [11]3 years ago

5 0

The sum of the first n terms in a geometric sequence given the first term (a1) and the common ratio (r) is calculated through the equation,

<span>Sn </span>= (<span><span><span>a1</span>(1−<span>r^n</span>) / (</span><span>1−r)

Substituting the known terms,
Sn = (20)(1 - (1/4)^4)) / (1 - 1/4)
Sn = 26.5625

Thus, the sum of the first four terms is 26.5625. </span></span>

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Find the value of the expression |2x−8| where x=−2.5; 0; 4; 5; 9.5.

Lelu [443]

The absolute value $|x|$ returns the "positive version" of a number. In other words, if $x$ is already positive, then $|x|=x$ . Otherwise, if $x$ is negative, then the absolute value changes its sign, so that it returns positive: $|x|=-x$ .

So, in this case, we have to plug the required values for $x$ in the expression $2x-8$ . Then, if the result is positive we're ok, otherwise we discard the negative sign.

We have:

$x=-2.5 \implies |2x-8| = |-5-8|=|-13|=13$

$x=0 \implies |2x-8| = |0-8|=|-8|=8$

$x=4 \implies |2x-8| = |8-8|=|0|=0$

$x=5 \implies |2x-8| = |10-8|=|2|=2$

$x=9.5 \implies |2x-8| = |19-8|=|11|=11$

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3 years ago

fref picked 1 4/9 bucket of lemons, and mary picked 1 1/12 buckets of lemons. How many buckets total did they pick

rewona [7]

You will have to add your whole then multiply your fraction

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3 years ago

What is the equation 2X plus 5Y equals 10 what is the table

Assoli18 [71]

Answer:ksksksk

Step-by-step explanation:ggg

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3 years ago

The ratio of students with brown eyes in Michelle’s class to all of the students in her class is 20:25. What is another way to w

harina [27]

Answer:

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8 0

3 years ago

7 qt. of a 27% saline solution was mixed

mamaluj [8]

Answer:

24% saline

Step-by-step explanation:

Find how much saline is in both solutions:

7(0.27)

= 1.89

3(0.17)

= 0.51

Add this together:

1.89 + 0.51

= 2.4

Since there are 10 quarts in total, the concentration of the mixture can be found by dividing 2.4 by 10:

2.4/10

= 0.24

So, the concentration of the mixture is 24% saline

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3 years ago