Mọi người ơi giúp mik nhanh câu này với ak. MIK SẼ VOTE 5 SAOOOOO
Tính nhanh:
a) 2022 x 2005 -2000 x 2022 + 15 x2022 – 20 x 2021
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
Lời giải:
PT $\Leftrightarrow (\frac{x+1}{2022}+1)+(\frac{x+2}{2021}+1)+...+(\frac{x+23}{2000}+1)=0$
$\Leftrightarrow \frac{x+2023}{2022}+\frac{x+2023}{2021}+...+\frac{x+2023}{2000}=0$
$\Leftrightarrow (x+2023)(\frac{1}{2022}+\frac{1}{2021}+...+\frac{1}{2000})=0$
Dễ thấy tổng trong () luôn dương
$\Rightarrow x+2023=0$
$\Leftrightarrow x=-2023$
\(\dfrac{2023}{2022}=\dfrac{2022}{2022}+\dfrac{1}{2022}=1+\dfrac{1}{2022}\)
\(\dfrac{2021}{2020}=\dfrac{2020}{2020}+\dfrac{1}{2020}=1+\dfrac{1}{2020}\)
\(\dfrac{1}{2022}< \dfrac{1}{2020}\)
\(\Rightarrow\dfrac{2023}{2022}< \dfrac{2021}{2020}\)
\(\dfrac{2023}{2022}=1+\dfrac{1}{2022}\)
\(\dfrac{2021}{2020}=1+\dfrac{1}{2020}\)
mà \(\dfrac{1}{2022}< \dfrac{1}{2020}\)
nên \(\dfrac{2023}{2022}< \dfrac{2021}{2020}\)
(125.72-5.352):20212022
=(53.72-53.72):20212022
=0:20212022
=0
100% ĐÚNG
\(\dfrac{2022\times2023-1}{2023\times2021+2022}\)
= \(\dfrac{\left(2021+1\right)\times2023-1}{2023\times2021+2022}\)
= \(\dfrac{2023\times2021+2023-1}{2023\times2021+2022}\)
= \(\dfrac{2023\times2021+2022}{2023\times2021+2022}\)
= 1
\(A=1+2^2+2^3+...+2^{2022}\)
\(\Rightarrow2A=2+2^3+2^4+...+2^{2023}\)
\(\Rightarrow A=2A-A=2+2^3+...+2^{2023}-1-2^2-...-2^{2022}=2-1+2^{2023}-2^2=-3+2^{2023}\)
A = 1 + 22 + 23 + ..... + 22021 + 22022
2A = 2(1 + 22 + 23 + ..... + 22021 + 22022)
2A = 2 + 23 + 24 + ..... + 22022 + 22023
2A - A = (2+23 + 24 + ..... + 22022 + 22023) - (1 + 22 + 23 + .... + 22021 + 22022 )
Thấy sai sai sao í -))
A = ( 2022 x 0,75 + 2022 : 4) - ( 2021 : 0,1 : 10)
= (2022 x 0,75 + 2022 x 0,25) - ( 2021 : 1/10 : 10)
= 2022 x(0,75+0,25) - 2021x 10 : 10
= 2022x 1 - 2021
= 2022 - 2021
=1
\(2022\times2005-2000\times2022+15\times2022-20\times2021\)
\(=2022\times\left(2005-2000+15\right)-20\times2021\)
\(=2022\times20-20\times2021\)
\(=20\times\left(2022-2021\right)\)
\(=20\times1\)
\(=20\)
a, 2022 \(\times\) 2005 - 2000 \(\times\) 2022 + 15 \(\times\) 2022 - 20 \(\times\) 2021
= (2022 \(\times\) 2005 - 2000 \(\times\) 2022 + 15 \(\times\) 2022 )- 20 \(\times\) 2021
= 2022 \(\times\) (2005 - 2000 + 15) - 20 \(\times\) 2021
= 2022 \(\times\) (5 +15) - 20 \(\times\) 2021
= 2022 \(\times\) 20 - 20 \(\times\) 2021
= 20 \(\times\) (2022 - 2021)
= 20 \(\times\) 1
= 20