$S_n=S_{n-2}\cdot (S_{n-1}-1)\quad \\\\S_1=2\quad given\\S_2=3\quad given\\S_3=S_1(S_2-1)\quad =2(3-1)\quad =4\\S_4=S_2(S_3-1)\quad =3(4-1)\quad =9\\S_5=S_3(S_4-1)\quad =4(9-1)\quad =32\\S_6=S_4(S_5-1)\quad =9(32-1)\quad =279\\S_7=S_5(S_6-1)\quad =32(279-1)\quad =8,896\\S_8=S_6(S_7-1)\quad =279(8896-1)\quad =2,481,705\\S_9=S_7(S_8-1)\quad =8896(2481705-1)\quad =22,077,238,784$

$\sum^8_{k=1}S_k\\\\=S_1+S_2+S_3+S_4+S_5+S_6+S_7+S_8\\\\= 2,490,924\\$

Neither

Not arithmetic because the difference between each of the terms is not the same.

S₂ - S₁ S₃ - S₂ S₄ - S₃

3 - 2 = 1 4 - 3 = 1 9 - 4 = 5

Not geometric because the ratios between each of the terms is not the same.

$\dfrac{S_2}{S_1}=\dfrac{S_3}{S_2}\qquad \rightarrow \dfrac{3}{2}=\dfrac{4}{3}\qquad \rightarrow \text{cross multiply to get}: 9\neq 8$

8 0

3 years ago

Problem 1.1.A basket of fruit is arranged out of apples, bananas, and oranges.What is the smallest number of fruit that should b

Vedmedyk [2.9K]

Answer:

Step-by-step explanation:

The question is based in pigeonhole principle that says If n or more pigeons are distributed among k >0 pigeonholes,then at least one pigeonhole contains at least $\frac{n}{k}$ pigeons.

8 + 6 + 9−3 + 1 = 21

3 0

2 years ago

Which expression can be used to model the phrase “ the sum of three and a number”?

olga nikolaevna [1]

Answer:

x + 3

Step-by-step explanation:

A 'sum' means addition, 'a number' is represented by a variable, in this case, I chose 'x'. I could have picked any variable I wanted.

The sum of three and a number means: three plus some number, which is

3 + x in math language. We write variables before constants, so it gets

rewritten as x + 3

5 0

3 years ago

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