ta có

1+2+3+.........+x=5050

=>\(\frac{x.\left(x+1\right)}{2}=5050\)

=>x.(x+1)=5050.2

=>x.(x+1)=10100

=>x.(x+1)=100.101

=>x=100

giúp mình với ,cần gấp

giúp mình với

a; 1 + 2 + 3 + ... + \(x\) = 5050

   Số số hạng của dãy số trên là: (\(x-1\)):1 + 1 = \(x\)

    (\(x\) + 1)\(\times\) \(x\): 2 =  5050

    (\(x\) + 1) \(\times\) \(x\)   = 5050 \(\times\) 2

    (\(x+1\)) \(\times\) \(x\)  = 10100

   (\(x+1\)) \(\times\) \(x\) = 101 \(\times\) 100

   Vậy \(x=100\)

ta có : \(5^x.5^{\left(x+1\right)}.5^{\left(x+2\right)}\le\dfrac{100...0}{2^{18}}\) \(\Leftrightarrow5^{3x+3}\le\dfrac{10^{18}}{2^{18}}=5^{18}\)

\(\)\(\Leftrightarrow3x+3\le18\Leftrightarrow x\le5\) vậy \(x\le5\)

cảm ơn nha

I.Each sentence below contains an error.Underline it and write the correct answer in the provided

Example0: There \(\dfrac{are}{ }\) an art gallery in our neighbourhood

0/is

1. I find carve=>carving eggshells boring because it takes a lot of time to complete one shell

2. My brother not goes=>doesn't go to class to learn how to paint

3. I take up=>took up this hobby when i came back home from the Art Gallery

4. I think playing volleyball interest=>interesting because it is a team game

5. In my opinion,more people played=>will play monopoly in the future

II.Fill each blank inthe following letter with a suitable word

Dear Mira,

Thanks for your letter.Now I'll tell you ABOUT my hobbies.My favourite hobby is skitting.It's trange,isn't it? My mother TAUGHT me to knit two years ago.Now I can knit scraves and seaters.It's great when I can GAVE them to my relatives and friends as gifts.Knitting is also imaginative AS you can knit anything you can imagine of.Besides,it is quite cheap.You only NEED a pair of needles and some wool.

I'm sending you a scarf next month.I'm knitting it.I hope you'll like it.

Best wishes,

Vy

có đúng k hả bạn