Was fine up until the x substitution, which wasn't really necessary. 81 x 82 x 10 is a straightforward multiplication which you can set out on paper anyway, instead of creating the quadratic equation, putting 80 back in as the value of x and then doing an addition of the constituent terms. That addition is part of the usual multiplication process so even if you (arguably) made the calculations easier, you made the journey longer!

Summation value=(1-r^n)(a)/(1-r) where r is the factor and a is the first term of the progression(a,ar,ar^2,ar^3,....,ar^n-1) where n is the no. Of terms

Directly calculating it is much easier😂

@frederic0chopin

2 ай бұрын

japanese people... lol

@torstenbroeer1797

24 күн бұрын

And very much faster!

@torstenbroeer1797

24 күн бұрын

As we say it in Germany: Why easy when it can be done complicated! The whole video is complete bullshit!

@subratahalder9725

9 күн бұрын

😂👍 yeah!

Solution is more complicated than the problem itself😮😮😮

普通に計算しても1分で終わる作業を、工夫して5分かけてるのが皮肉っぽくて好き

Не проще 81 на 82 перемножить столбиком? Далее приписываем ноль справа и прибавляем 9.

@alexeyponomarev1933

2 ай бұрын

Советская школа - самая лучшая! А эти пока решат... На горе рак свиснет

@user-bk1wl9ez1c

2 ай бұрын

Просто розписати формулу суми геометр. прогресії.

Maybe not easier, but I got it in a different way. 9=(10-1), so we get this bracket in different powers and can write (10-1)^5=10^5-5*10^4+10*10^3-10*10^2+5*10-1, transform the other powers likewise and add similar terms (with the same powers). This is easy if you're familiar with Pascal's triangle or Binomial theorem. Finally you get 10^5 - 4*10^4 + 7*10^3 - 6*10^2 + 3*10 - 1 = 10^5 - 10^3*(40-7) - 10^2*(60-3) - 1, which is easy to calculate. Powers of ten and simple addition and subtraction

@nalim81

Ай бұрын

+1 for this way. It is more universal if we consider an alternative for simple multiplication and addition, pure calculation with no equations. Should help with similar problems until the binomial coefficients grow too large, e.g. 9^9+9^8+...+9.

LOL and I stayed to see it till the end. There are some other videos like this. Why not make it more complicated than it should be.

We can just rewrite it in nonary 111110(9), and we find that 1000000(9) - 1(9) = 888888(9) 888888(9) / 8(9) = 111111(9) 111111(9) - 1(9) = 111110(9), which means (9^6 - 1) / 8 - 1 in decimal. We can write it as (9^3 + 1)(9^3 - 1) / 8 - 1 = 730 * 728 / 8 - 1 = 730 * 91 - 1 = 66430 - 1 = 66429

@profdinossauro

2 ай бұрын

No need to use nonary, just use geometric progression for the same process, its easy for people understand.

Simplemente hermoso. Muy buen ejercicio para mis hijos. Muchas gracias amgio.

@learncommunolizer

Ай бұрын

Thank you very much

👍

That was helpful!!!!!! Thanks Alot

@learncommunolizer

3 ай бұрын

You're welcome! Thank you very much

Excellent!

@learncommunolizer

3 ай бұрын

Thank you very much!!

Why are you complicating things, anyhow you are multiplying numbers in the end. Why can’t you just calculate the value by just multiplying and adding in the beginning

What a round about way. U cd hv taken 9 power 2common and made it simple .

Equal =9*((1-9^5)/(1-9))=66429 😅

The solving process is really hilarious. man, you make my day!

Muito bom. Very Nice

@learncommunolizer

Ай бұрын

Thank you very much ❤

Very nice solution!

@learncommunolizer

Ай бұрын

Thank you! Cheers!

Thanks. It was very interesting. And helpful.

@learncommunolizer

Ай бұрын

Glad it was helpful! Thank you very much

This is Arithmetic Progression, it's just a complicated formula

I’m amazed

Good

@learncommunolizer

Ай бұрын

Thanks

Se fizer direto é muito mais fácil e rápido...

U can tdirect take common (9+1) No need to expand lines

So 81*82 is incalculable on paper?😅😅

@christianeb8494

3 ай бұрын

Sure. The rest is not usefull. Hello from France.

@pto314

3 ай бұрын

Yes, if you know how to square a 2-digit number mentally. 81*82=81^2+81=6561+81=6642 😊

@christianeb8494

3 ай бұрын

@@pto314 Simply.

@SM-yi5cs

Ай бұрын

1:37

111110 nonary to decimal = 66429😂

Seems like it would have been a lot faster to multiply everything in the first place and then add them all up

very beautiful :)

@learncommunolizer

Ай бұрын

Thank you very much !

That is a geometrical prrogression, extremely simple But It Is interesting with this alternative strategy, It can be rewritten as polynomial equation too

Good!!! Brasil

Я думал, что это окажется интересным, так как считал что это переменные, но когда увидел, что он пишет 10, я осознал, что это всего лишь числа.

Why don't you use Geometric progression concept

@ace6285

2 ай бұрын

This is for people who don’t know that.

this time, the way of solution is not so beautiful or easy unlike other. There must be some reason for this elaborate solution that I couldn't find out.

Suit géométrie

Good luck,❤❤❤❤❤❤❤❤❤❤❤❤❤❤❤❤❤❤❤❤❤❤❤❤❤❤❤❤❤❤❤❤❤❤❤❤❤❤❤❤❤

@learncommunolizer

2 ай бұрын

Thank you very much ❤️❤️❤️

Multiplicator x, ., or space?

Soma dos termos de uma PG

What is this solution???? It is simply equal to (9^6 - 1)/(9 - 1)

Fazer a operação natural é bem mais simples.

No necesité lápiz y papel para resolverlo. Buen ejercicio 🤙

Это совсем просто. Овет: 111110 в девятеричной системе счисления. ИЛИ: 9^6 - 10

Unnecessary added substitutions. Could be solved earlier.

Damn it!, why would people waste their precious time doing this stuff in Olympiads

Why so long and complicated method? Direct calculation is much more easier

9 to the power 15. Easy

@Prem-K007

29 күн бұрын

How can you say that ?😢 You said that simply , without even thinking , the actual answer is 66,429 . 9¹⁵ is somewhere around 2.05 ×10¹⁴ , which is nearly 3.01 million times the actual answer , you went too far away (too many light years far) . So , yes , it's as simple as that . Edit:- I assume that you added the powers of 9s ,you should do that when they are getting multiplied , not when they are added. It's okay , beginners' mistake!

Hayatımda böyle saçma sapan soru çözme şekli görmedim. Hintli öğrencilerin neden intihar ettiklerini şimdi daha iyi anlıyorum.

66429

Очень мешало то, что цифра "9" воспринималась как буква "g".

Last part should be 6642 * 19

مول الحانوت لمسرهط : أصلا باش تخرج ليك شي فاكتورة بحال هادي فالواقع و ماتكونش عندك زعمى الكالكيلاتغيس راه شبه مستحيل!🍋 العالم الرايق : و حتى انا فالحياة العلمية!🍋👻😁

Если решить быстрее, лишат гражданства?

I feel tired when you solve the problem.. thats not easy way..

А просто по ф- Ле геометрия. Прогрессии?

66429 easy

66429.

а через синусы с косинусами не пробовал решать? чё, сразу-то в 5-ю степень слабо возвести??? 81х81х9 Voilà ! Привет из России!

9 ki power 15

@Prem-K007

29 күн бұрын

How can you say that ?😢 You said that simply , without even thinking , the actual answer is 66,429 . 9¹⁵ is somewhere around 2.05 ×10¹⁴ , which is nearly 3.01 million times the actual answer , you went too far away (too many light years far) . So , yes , it's as simple as that . Edit:- I assume that you added the powers of 9s ,you should do that when they are getting multiplied , not when they are added. It's okay , beginners' mistake!

why not just calculate (9^6-1)/8‐(9^0)😂

@d2r2_M1

3 ай бұрын

Come on, just without a calculator please!! With a calculator you don’t have to convert anything at all.

@aisawaloki1571

3 ай бұрын

@@d2r2_M1 you can still calculate those several 9^x without calculators This is just equal to 111110 in base-9

@Prem-K007

29 күн бұрын

(9⁶-9)/8

This is of no use in practical life .....!!

9^6 - 1

@Prem-K007

29 күн бұрын

Wrong bro , (9⁶-9)/8 is right answer . Well , nice try!

@TAPESOLAR

29 күн бұрын

@@Prem-K007 in fact would be 9^6 - 9

❤❤🥹👏👏👍👍

Sorry .. people can't simply multiply and add these in their head? Wow.

@jamesharmon4994

3 ай бұрын

I'm not bad in math (I calculate sales tax in my head), but I can't do 9^5 + 9^4 in my head.

@LeonardoTessari

3 ай бұрын

​@jamesharmon4994 it's just multiply 9*9 and then multiply the former for 9

@jamesharmon4994

3 ай бұрын

@LeonardoTessari that's only 9^3. Now multiply that by 9 in your head to get 9^4. Then multiply by 10 and add 819 in your head.

@LeonardoTessari

3 ай бұрын

@@jamesharmon4994 yes you have to do five moltiplications and one sum. It seems easier than all the calculus in the videos

@jamesharmon4994

3 ай бұрын

@LeonardoTessari If you can do this problem with no calculator or paper, strictly in your head, I'm jealous. I love calculus, but I need paper.

Об,яснение для недоумков- мне 78лет

@d2r2_M1

3 ай бұрын

Бывает! Но я думаю ты изложишь свои ход мыслей. Или как обычно?

멍청한 짓.

Deliberate punishment and waste of ink and paper. All for views.

Tu nahi bana paiga

@Prem-K007

29 күн бұрын

He did it bro, watch till end

Right Answer 66.429

Сложить степени❗

為啥要向日本叫囂？

I got 66429 and pretty easy this problem is, isn't it? ...so is this really on the olympic level? Le p'tit Daniel

@jamesharmon4994

3 ай бұрын

I've seen a few easy questions supposedly rated olympiad, which makes me suspect there is a "Primary School Olympiad".

@PS-mh8ts

3 ай бұрын

@@jamesharmon4994 no, it's a click-bait. don't be surprised if you find a question such as "what is the sum of 1 and 2 taiwan olympiad preparation"

Yanlış alakasız sacna bisey yaptı. Cevap 538821

more complicated，you have to learn from china.

66429

@rolandpokorny2813

3 ай бұрын

result 9^14 = 2,2876 x 10^13

@ekariniwahyuningsih5461

3 ай бұрын

​@@rolandpokorny2813that is not how it works.it is if were multiplication but this is addition

@Prem-K007

29 күн бұрын

​​​​​@@rolandpokorny2813 wrong ! Use atleast common sense , we know that : 10⁵>9⁵ , and sum of (10⁵+10⁴+10³+10²+10¹) will be always less than 10⁶ and it does not exceed it at all . In this case , the answer should be less than 9⁶ and also less than 10⁵ . Let's compare with your answer : some 'a' × 10¹³ My god ! 😱. I took 10 as example because which is near to 9 and you know it's easy to decode. Please don't get offended by this. Edit:- well , the calculation of 9¹⁴ is right but that's not required here.

@Prem-K007

29 күн бұрын

Do you speak Telugu?

66429