Ask question

Ask question

All categories

4 years ago

13

What is the sum of the geometric sequence 1,-6,36... if there are 6 terms

1 answer:

zalisa [80]4 years ago

7 0

$a_1=1;\ a_2=-6;\ a_3=36;\ ...\\\\r=a_2:a_1\to r=-6:1=-6\\\\S_n=\dfrac{a_1(1-r^n)}{1-r}\\\\a_1=1;\ r=-6;\ n=6\\\\subtitute\\\\S_6=\dfrac{1(1-(-6)^6)}{1-(-6)}=\dfrac{1-46656}{1+6}=\dfrac{46655}{7}=6665$

You might be interested in

Guys help me with this question please. Due Now

boyakko [2]

F(5) = 21
look on the table and find where x=5 on the top row, the number that is with it is 21

f(x) = 7
x=6
look on the table and find where f(x)=7 on the bottom row, the number with it is 6

6 0

3 years ago

What is 1/10 + 50/100?

erastovalidia [21]

Answer:

$\large\boxed{\dfrac{3}{5}=0.6}$

Step-by-step explanation:

$\bold{METHOD\ 1:}\\\\\dfrac{1}{10}+\dfrac{50}{100}=\dfrac{1}{10}+\dfrac{50\!\!\!\!\diagup}{100\!\!\!\!\diagup}=\dfrac{1}{10}+\dfrac{5}{10}=\dfrac{1+5}{10}=\dfrac{6}{10}=\dfrac{6:2}{10:2}=\dfrac{3}{5}\\\\\bold{METHOD\ 2:}\\\\\text{Convert the fractions to decimal:}\\\\\dfrac{1}{10}=0.1\\\\\dfrac{50}{100}=0.50=0.5\\\\\dfrac{1}{10}+\dfrac{50}{100}=0.1+0.5=0.6$

4 0

4 years ago

AC is tangent to circle o at point c. what is the length of ac?

Readme [11.4K]

Answer:

4

Step-by-step explanation:

6 0

4 years ago

estimate time stuffing 150 envelopes with one insert, stamp, address label, return address label and sealing

Rzqust [24]

Roughly around an hour and a half.

3 0

3 years ago

Read 2 more answers

El recorrido de una etapa de una vuelta ciclística tiene una longitud de 213 kilometros y un ciclista recorre 2/3 del trayecto e

Maurinko [17]

the question in English

The route of a stage of a cycle tour is 213 km long and a cyclist covers 2/3 of the route in five hours.

a) How many kilometers are left to finish the stage?

b) If he continues with the same average speed, how much time does he have left to finish the stage?

Step 1

we know that

1) Total kilometers of a stage is $213\ km$

2) The cyclist covers $\frac{2}{3}$ of the route

so

the kilometers remaining to finish the stage is equal to

$(1-\frac{2}{3})*213= \frac{1}{3}*213\\ \\=71\ km$

therefore

<u>the answer Part a) is </u>

$71\ km$

Step 2

<u>Find the average speed of the cyclist</u>

we know that

the speed is equal to

$speed=\frac{distance}{time}$

we have

$time=5\ hours\\ distance=\frac{2}{3}*213=142\ km$

substitute

$speed=\frac{142}{5}=28.4\frac{km}{h}$

Step 3

<u>Find the time remaining to finish the stage</u>

we know that

$speed=\frac{distance}{time}$

Solve for the time

$time=\frac{distance}{speed}$

we have

$distance=71\ km\\ speed=28.4\frac{km}{h}$

substitute

$time=\frac{71}{28.4}=2.5\ hours$

therefore

<u>the answer Part b) is</u>

$2.5\ hours$

8 0

3 years ago