Formula of 1 1 / 3 9 / 35 17 / 63 33 / 99

Formula of 1 1 / 3 9 / 35 17 / 63 33 / 99

It can be recorded as: 1 5 / 15 9 / 35 17 / 63 33 / 99
The numerator is: 2 ^ n + 1 from the second term
The denominator is (2n-1) (2n + 1) from the second term
So the general formula of this sequence is: A1 = 1, an = (2 ^ n + 1) / [2n-1) (2n + 1) n > = 2

① 7x9 = 63, 8x8 = 64, ② 11x13 = 143, 12x12 = 144, ③ 79x81 = 6399, 80x80 = 6400, what rules have been found

It is found that (n-1) (n + 1) = n & # 178; - 1

In one exam, the scores of 14 students in a class are as follows: 79, 81, 95, 92, 68, 75, 08, 93, 85, 65, 72, 75, 80, 87
【1】 80 is the benchmark. If the score is higher than 80, mark it as "positive" and if the score is lower than 80, mark it as "negative". Please show the scores of these 14 students according to the above requirements, and use the scores in [1] to calculate their average score

-1,+1,+15,+12,-12,-5,0,+13,+5,-15,-8,-5,0,+7
Average score = 80 + (- 1 + 1 + 15 + 12-12-5 + 0 + 13, + 5, - 15, - 8, - 5 + 0, + 7) / 14
=80+7/14
=80.5

Fourth grade comprehensive formula 208-36 = 172 8 × 26 = 208 144 △ 4 = 36 comprehensive formula

8 ×26-144÷4
=208-36
=172

English translation
The positive impact of the Internet
1. It can make our communication more convenient and eliminate many restrictions
2. It can cultivate the communication ability of all kinds of people
3. Get the latest information as soon as possible
The negative influence of Internet
1. Easy to indulge in the Internet and waste their time and energy
2. There are a lot of bad information on the Internet
I only think of so much for the time being. Can I help you to supplement it

La influencia positiva de internet1.Hace comunicar más fácil y evitar mucha limitacíon.2.Praticar y acumular la capacidad de comunicar con diferentes personas .3.Conocer las últimas noticias más ...

English translation
Love you is my biggest pain
Then help me find a word similar to Agoni in Spanish

Love you is my biggest pain!
Me Encant ó Tu eres Mi mayor Dolor!

English translation
La Liga and Spain are famous all over the world, especially Spain won the world cup in South Africa in 2010. I like Barcelona very much, especially Messi of Barcelona. Messi is a great player

La liga española y la selección tienen fama por todo el mundo,además la selección roja ganó el campeonato de la copa mundial en Sudá frica.Me gusta mucho el equipo azulgrana,especialmente Messi,es un jugador maestro.
Take points, ho ho

English translation
hola donde estas yo me llamo Esteban sos de Madrid¿

Hola Donde estas where are you yo me llamo Estan my name is Estan this sentence is a bit wrong, it should be so y, not so so y de Madrid I'm from Madrid

English translation
El olvido es el único perdón y la única venganza".J.L.Borges. 

Forgetting is the only forgiveness and revenge - JL Borges

English translation
Yes, what are you doing there?
I want to learn Spanish
Where is XXX, please?

How long has this celadon learned? Is this Spanish a little too Chinese I'll give you an answer, but I can't stress my computer after it's reinstalled
1. S í, y para que (E) vas all í
2、Quiero aprender espa?ol.
3. Podr í a decirme Donde esta
With respect to my ignorance, that de Mayo is really unheard of I don't have a dictionary. I'm open-minded