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ANTONII [103]
2 years ago
14

Lucy is working with a series whose first term is 12 and that is generated by the equation t(n) = −9 + 21n. The sum of her serie

s is 3429. How many terms are in her series? *hint: the last term can be written as -9 + 21n if we say there are n terms. You will need to solve a quadratic equation to solve for n.
Mathematics
1 answer:
mafiozo [28]2 years ago
7 0

There are 18 terms are in her series

<h3>What is Arithmetic progression series?</h3>

Arithmetic Progression (AP) is a sequence of numbers in order in which the difference of any two consecutive numbers is a constant value.

Given that: t(n) = −9 + 21n=l

a= 12, Sum = 3429

As, Sum of series =3429

     n/2 (a+l) =3429

     n/2 (12 +21n-9)= 3429

     n/2 (3+21n)=3429

     21n² + 3n= 6858

     21n² + 3n- 6858=0

    7n² + n- 2286=0

For solving for n, get

    n= 18 or n= -127/7

Thus, there 18 terms in the series.

Learn more about series here:

brainly.com/question/12146981

#SPJ1

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at a football game 95% of people attending were supporting the home team while 5% were supporting the visiting team. if the tota
Paraphin [41]

Answer:

3800

Step-by-step explanation:

The first step you want to do is make a proportion

x/4000=95/100

Next you are going to cross multiply which his 4000 times 95 equals 380000 and then multiply 100 times x which is 100x.

Then you are going to divide both sides by 100 and you will cross out the x from the 100 and get only x and then divide 380000 divided by 100 and 3800

Which leaves you with x=3800

3800 people were attending to support the home team

Hope this helps :)

5 0
3 years ago
What is 324,120,800 in scientific notation​
Maru [420]
3.241208 × 10 to the eighth power
4 0
3 years ago
Lena walks 2.5km every day. How far does she walk in 7 days? Write your answer in meters.
Marat540 [252]

Answer:

17.5 meters

Step-by-step explanation:

To find how far she walks, multiply 2.5 by 7

2.5(7)

= 17.5

So, in 7 days, she walks 17.5 meters

6 0
3 years ago
Assignment
kvv77 [185]

Answer:

12

step by step equation:

Lindsay owns 12 books.

Step-by-step explanation:

We can solve this question using a system of equations.

I am going to say that:

x is the number of books that Lindsay owns.

y is the nuber of books that Destiny owns.

z is the number of books that Henry owns.

Lindsay owns one-third the number of books that Destiny owns.

This means that:

, or

Henry owns a fourth as many books as Destiny.

This means that , or . Also, in function of x, we may have

Together they own 57 books.

This means that

We want to find x. So

Lindsay owns 12 books.

6 0
3 years ago
The population of a country grows exponentially at a rate of 1% per year. If the population was 35.7 million in the year 2010, t
Lady_Fox [76]

Answer:

37.52 million

Step-by-step explanation:

using,

A = A'(1+R/100)ⁿ............................. equation 1

Where A = population size in 2015, A' = Initial population, R = rate in percentage, n = number of times between 2010 and 2015.

Given: A' =35.7 million, R = 1%, n = 5.

Substitute these values into equation 1

A = 35.7(1+0.01)⁵

A = 37.52 million.

Hence the size of the population of the country in the year 2015 is 37.52 million

7 0
3 years ago
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