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2 years ago

What is the sum of the first 4 terms of a geometric sequence that has a first term of 2 and a ratio (multiplier) of 8?

1 answer:

6 0

$\bf \qquad \qquad \textit{sum of a finite geometric sequence} \\\\ S_n=\sum\limits_{i=1}^{n}\ a_1\cdot r^{i-1}\implies S_n=a_1\left( \cfrac{1-r^n}{1-r} \right)\quad \begin{cases} n=n^{th}\ term\\ a_1=\textit{first term's value}\\ r=\textit{common ratio}\\ ----------\\ a_1=2\\ r=8\\ n=4 \end{cases} \\\\\\ S_4=2\left( \cfrac{1-8^4}{1-8} \right)\implies S_4=2\left( \cfrac{-4095}{-7} \right) \\\\\\ S_4=2(585)\implies S_4=1170$

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Find the fifth term in the sequence that is defined as follows:

hram777 [196]

Answer : The fifth term in the sequence is -2.

Step-by-step explanation :

As we are given that the expression to calculate the $n^{th}$ term.

The expression is as follows:

$a_n=2(-1)^n$

where,

n is the number of term

Given:

n = 5

Now putting the value of n in the above expression, we get:

$a_n=2(-1)^n$

$a_5=2(-1)^5$

$a_5=2\times (-1)$

$a_5=-2$

Therefore, the fifth term in the sequence is -2.

5 0

3 years ago

Which expression is equivalent to the expression –6.4 – 12 + 4.6?

kow [346]

The answer is -13.8.

Hope this helps!

6 0

3 years ago

Which choice most effectively combines the

shepuryov [24]

The subject-verb agreement: "Writing as" effectively combines the sentences at the underlined portion.

<h3>What is a Subject-Verb Agreement?</h3>

The grammatical principle of the subject-verb agreement states that a sentence's subject and primary verb must agree.
Particularly, singular subjects use singular verbs, whereas plural subjects use plural verbs.
There must be an agreement between the number of subjects and verbs (singular or plural).
This means that if a subject is singular, then the verb must likewise be singular, and if a subject is a plural, then the verb must also be numerous. verbs DO NOT include "an, s" in their single forms.

Therefore option (A) is the correct answer.

To learn more about Subject-Verb Agreement, refer:

brainly.com/question/1835508

#SPJ4

The underlined sentence is:

Also, studies have found that those students who major in philosophy often do better than students from other majors in both verbal reasoning and analytical <u>writing. These results</u> can be measured by standardized test scores. On the Graduate Record Examination (GRE), for example, students intending to study philosophy in graduate school have scored higher than students in all but four other majors.

7 0

1 year ago

at the zoom,the ratio of monkeys to gorrillas is 5:2 if there were 20 monkeys how many gorrilas would there be?

Umnica [9.8K]

8 gorrilas

Explanation:

The ratio of monkeys to gorrila = 5:2

This means there are 5 monkeys for every 2 gorrilas

when there are 20 monkeys,

let the number of gorrilas = x

5 monkeys = 2 gorrilas

20 monkeys = x

cross multiply:

5(x) = 20(2)

5x = 40

divide both sides by 5:

5x/5 = 40/5

x = 8

Hence, if there were 20 monkeys, we would have 8 gorrilas.

5 0

11 months ago

Look at the question

ziro4ka [17]

Answer:

Step-by-step explanation:

The better buy is the one where you get more area of pizza per dollar (area/price).

Since the problem gives diameter, we assume the pizzas are circle-shaped.

Circle Area = pi x (radius)², and radius r = 1/2 of diameter d.

*************************************************************************************

Pizza 1: d = 8 and price is $10

r = 1/2 x d = 4

Area of Pizza 1 = πr² = π(4)² = 16π

*** area/price for Pizza 1 = 16π/$10 = 1.6π area per dollar

**********************************************************************************

Pizza 2: d = 14 and price is $16

r = 1/2 x d = 7

Area of Pizza 2 = πr² = π(7)² = 49π

*** area/price for Pizza 2 = 49π/16 = 3.0625π area per dollar

***********************************************************************************

Pizza 2 is the better buy, with more pizza per dollar.

3 0

3 years ago