$\left(1^2+2^2+3^2+...+2021^2\right)\cdot \left(91-273:3\right)$
$=\left(1^2+2^2+3^2+...+2021^2\right)\cdot \left(91-91\right)$
$=\left(1^2+2^2+3^2+...+2021^2\right)\cdot 0$
$=0$

$12^{30}:216^{n+1}=8^{10}$

=>$216^{n+1}=\genfrac{}{}{0ex}{}{12^{30}}{8^{10}}=\genfrac{}{}{0ex}{}{{\left(12^3\right)}^{10}}{8^{10}}=216^{10}$

=>n+1=10

=>n=10-1=9

326 + (153 - x) = 403

=> 153 - x = 403 - 326

=> 153-x=77

=> x=153-77

=>x=76

Vậy: x=76

nhìn mà thấy vui lây lun mấy bạn ơi.☺☺

☺☺☺☺

ko chép mạng tui chép nó.

A: Happy New Year, everyone! Welcome in!

B: Happy New Year, A! Your house looks great.

C: Yes, the Tet atmosphere is so warm. The smell of Banh Chung is wonderful!

A: Thank you both. D, you're here too! Happy New Year!

D: Happy New Year, A! Wishing you and your family a prosperous new year.

B: D, you brought so much!

D: These are small gifts for A's family for the new year. Some candies, jams, and fruit.

A: You're too kind. Everyone, come in and have some tea and chat. It's Tet, let's just relax.

C: Exactly, the important thing is we're all together.

A: That's right. Now, let's raise a glass to the new year!

B, C, D: Happy New Year!

(-4)+6=2(⁰c)

ta có: A= 5 + 52 + 53 + ... + 52024

5A = 52 + 53 + 54 + ... + 52025

5A - A = (52 + 53 + 54 + ... + 52025) - (5 + 52 + 53 + ... + 52024)

4A = 52 + 53 + 54 + ... + 52025 - 5 - 52 - 53 - .. - 52024

4A = (52 - 52) + (53 - 53) + ... + (52024 - 52024) + (52025 - 5)

4A = 0 + 0 + 0+ .. + 0+ 52025 - 5

4A = 52025 - 5

A = $\genfrac{}{}{0ex}{}{5^{2025}-5}{4}$ 

?????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????