Tìm x biết 1/1*2 + 1/2*3 + ... + 1/x(x+1)=2022/2023
Tìm x, biết:
( \(\dfrac{1}{2}\) + \(\dfrac{1}{3}\) + \(\dfrac{1}{4}\) + ... + \(\dfrac{1}{2023}\) ) . x = \(\dfrac{2022}{1}\) + \(\dfrac{2021}{2}\) + \(\dfrac{2020}{3}\)
+ ... + \(\dfrac{1}{2022}\)
(\(\dfrac{1}{2}+\dfrac{1}{3}+\dfrac{1}{4}+...+\dfrac{1}{2023}\)). x = (\(\dfrac{2021}{2}+1\))+(\(\dfrac{2020}{3}+1\))+....+(\(\dfrac{1}{2022}+1\))
(\(\dfrac{1}{2}+\dfrac{1}{3}+\dfrac{1}{4}+...+\dfrac{1}{2023}\)). x = \(\dfrac{2023}{2}\)+\(\dfrac{2023}{3}\)+....+ \(\dfrac{2023}{2022}\)
(\(\dfrac{1}{2}+\dfrac{1}{3}+\dfrac{1}{4}+...+\dfrac{1}{2023}\)). x = 2023.( \(\dfrac{1}{2}+\dfrac{1}{3}+\dfrac{1}{4}+...+\dfrac{1}{2023}\))
vậy x= 2023
tìm x biết: x+1/2019+x+2/2018+x+3/2017=x-1/2021+x-2/2022+x-3/2023
\(\frac{x+1}{2019}+\frac{x+2}{2018}+\frac{x+3}{2017}=\frac{x-1}{2021}+\frac{x-2}{2022}+\frac{x-3}{2023}\)
\(\Leftrightarrow\left(\frac{x+1}{2019}+1\right)+\left(\frac{x+2}{2018}+1\right)+\left(\frac{x+3}{2017}+1\right)=\left(\frac{x-1}{2021}+1\right)+\left(\frac{x-2}{2022}+1\right)+\left(\frac{x-3}{2023}+1\right)\)
\(\Leftrightarrow\left(\frac{x+1+2019}{2019}\right)+\left(\frac{x+2+2018}{2018}\right)+\left(\frac{x+3+2017}{2017}\right)=\left(\frac{x-1+2021}{2021}\right)+\left(\frac{x-2+2022}{2022}\right)+\left(\frac{x-3+2023}{2023}\right)\)
\(\Leftrightarrow\frac{x+2020}{2019}+\frac{x+2020}{2018}+\frac{x+2020}{2017}=\frac{x+2020}{2021}+\frac{x+2020}{2022}+\frac{x+2020}{2023}\)
\(\Leftrightarrow\frac{x+2020}{2019}+\frac{x+2020}{2018}+\frac{x+2020}{2017}-\frac{x+2020}{2021}-\frac{x+2020}{2022}-\frac{x+2020}{2023}=0\)
\(\Leftrightarrow\left(x+2020\right)\left(\frac{1}{2019}+\frac{1}{2018}+\frac{1}{2017}-\frac{1}{2021}-\frac{1}{2022}-\frac{1}{2023}\right)=0\)
Vì \(\frac{1}{2019}+\frac{1}{2018}+\frac{1}{2017}-\frac{1}{2021}-\frac{1}{2022}-\frac{1}{2023}\ne0\)
=> x + 2020 = 0
=> x = -2020
Bài làm :
Ta có :
\(\frac{x+1}{2019}+\frac{x+2}{2018}+\frac{x+3}{2017}=\frac{x-1}{2021}+\frac{x-2}{2022}+\frac{x-3}{2023}\)
\(\Leftrightarrow\left(\frac{x+1}{2019}+1\right)+\left(\frac{x+2}{2018}+1\right)+\left(\frac{x+3}{2017}+1\right)=\left(\frac{x-1}{2021}+1\right)+\left(\frac{x-2}{2022}+1\right)+\left(\frac{x-3}{2023}+1\right)\)
\(\Leftrightarrow\left(\frac{x+1+2019}{2019}\right)+\left(\frac{x+2+2018}{2018}\right)+\left(\frac{x+3+2017}{2017}\right)=\left(\frac{x-1+2021}{2021}\right)+\left(\frac{x-2+2022}{2022}\right)+\left(\frac{x-3+2023}{2023}\right)\)
\(\Leftrightarrow\frac{x+2020}{2019}+\frac{x+2020}{2018}+\frac{x+2020}{2017}=\frac{x+2020}{2021}+\frac{x+2020}{2022}+\frac{x+2020}{2023}\)
\(\Leftrightarrow\frac{x+2020}{2019}+\frac{x+2020}{2018}+\frac{x+2020}{2017}-\frac{x+2020}{2021}-\frac{x+2020}{2022}-\frac{x+2020}{2023}=0\)
\(\Leftrightarrow\left(x+2020\right)\left(\frac{1}{2019}+\frac{1}{2018}+\frac{1}{2017}-\frac{1}{2021}-\frac{1}{2022}-\frac{1}{2023}\right)=0\)
\(\text{Vì : }\frac{1}{2019}+\frac{1}{2018}+\frac{1}{2017}-\frac{1}{2021}-\frac{1}{2022}-\frac{1}{2023}\ne0\)
\(\Rightarrow x+2020=0\Leftrightarrow x=-2020\)
Vậy x=-2020
\(\frac{x+1}{2019}+\frac{x+2}{2018}+\frac{x+3}{2017}=\frac{x-1}{2021}+\frac{x-2}{2022}+\frac{x-3}{2023}\)
\(\Leftrightarrow\left(\frac{x+1}{2019}+1\right)+\left(\frac{x+2}{2018}+1\right)+\left(\frac{x+3}{2017}+1\right)=\left(\frac{x-1}{2021}+1\right)+\left(\frac{x-2}{2022}+1\right)+\left(\frac{x-3}{2023}+1\right)\)
\(\Leftrightarrow\frac{x+1+2019}{2019}+\frac{x+2+2018}{2018}+\frac{x+3+2017}{2017}=\frac{x-1+2021}{2021}+\frac{x-2+2022}{2022}+\frac{x-3+2023}{2023}\)\(\Leftrightarrow\frac{x+2020}{2019}+\frac{x+2020}{2018}+\frac{x+2020}{2017}=\frac{x+2020}{2021}+\frac{x+2020}{2022}+\frac{x+2020}{2023}\)
\(\Leftrightarrow\frac{x+2020}{2019}+\frac{x+2020}{2018}+\frac{x+2020}{2017}-\frac{x+2020}{2021}-\frac{x+2020}{2022}-\frac{x+2020}{2023}=0\)
\(\Leftrightarrow\left(x+2020\right)\left(\frac{1}{2019}+\frac{1}{2018}+\frac{1}{2017}-\frac{1}{2021}-\frac{1}{2022}-\frac{1}{2023}\right)=0\)
\(\Leftrightarrow x+2020=0\)
\(\Leftrightarrow x=-2020\)
(X-1)/2023 +(x-2)/2022+( x-3)/2023+...+(x-2022/2
Sửa đề: \(\frac{x-1}{2023}+\frac{x-2}{2022}+\cdots+\frac{x-2022}{2}=2022\)
Ta có: \(\frac{x-1}{2023}+\frac{x-2}{2022}+\cdots+\frac{x-2022}{2}=2022\)
=>\(\left(\frac{x-1}{2023}-1\right)+\left(\frac{x-2}{2022}-1\right)+\cdots+\left(\frac{x-2022}{2}-1\right)=2022-2022=0\)
=>\(\frac{x-2024}{2023}+\frac{x-2024}{2022}+\cdots+\frac{x-2024}{2}=0\)
=>\(\left(x-2024\right)\left(\frac{1}{2023}+\frac{1}{2022}+\cdots+\frac12\right)=0\)
=>x-2024=0
=>x=2024
Tìm x, biết \(\left|x+1\right|^{2022}+\left|x+2\right|^{2023}=1\)
Online gấp nha!
Ta thấy \(\left|x+2\right|\) hơn \(\left|x+1\right|\) 1 đơn vị
Mà \(\left|x+1\right|\ge0\) \(\Rightarrow\left|x+1\right|^{2022}\ge0\)
\(\Rightarrow\left|x+2\right|\ge1=>\left|x+2\right|^{2023}\ge1\)
\(\Rightarrow\left|x+1\right|^{2022}+\left|x+2\right|^{2023}\ge1\)
Dấu '' = '' xảy ra khi \(\left\{{}\begin{matrix}x+1=0\\x+2=1\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}x=-1\\x=-1\end{matrix}\right.\Rightarrow x=-1\)
Vậy phương trình có nghiệm x = -1
x còn có thể có TH -2 mà bn
\(x=-2=>\left|-2+1\right|^{2022}+\left|-2+2\right|^{2023}=1+0=1\)
Nh vẫn cảm ơn nha
tìm x 2-x/2021 -1 = 1-x/2022 - x/2023
=>\(\left(\dfrac{2-x}{2021}-1\right)=\left(\dfrac{1-x}{2022}-1\right)+\left(1-\dfrac{x}{2023}\right)\)
=>2023-x=0
=>x=2023
tìm x
(x+1)/2023 + (x+2)/2022=(x+3)/2021 + (x+4)/2020
\(\dfrac{x+1}{2023}+\dfrac{x+2}{2022}=\dfrac{x+3}{2021}+\dfrac{x+4}{2020}\\ \Leftrightarrow\dfrac{x+1}{2023}+1+\dfrac{x+2}{2022}+1=\dfrac{x+3}{2021}+1+\dfrac{x+4}{2020}+1\\ \Leftrightarrow\dfrac{x+1+2023}{2023}+\dfrac{x+2+2022}{2022}-\dfrac{x+3+2021}{2021}-\dfrac{x+4+2020}{2020}=0\\ \Leftrightarrow\left(x+2024\right)\times\left(\dfrac{1}{2023}+\dfrac{1}{2022}-\dfrac{1}{2021}-\dfrac{1}{2020}\right)=0\\ \Rightarrow x+2024=0:\left(\dfrac{1}{2023}+\dfrac{1}{2022}-\dfrac{1}{2021}-\dfrac{1}{2020}\right)\\ \Rightarrow x+2024=0\\ \Rightarrow x=-2024\)
`(x+1)/2023+(x+2)/2022=(x+3)/2021+(x+4)/2020`
`=>(x+1)/2023+1+(x+2)/2022+1=(x+3)/2021+1+(x+4)/2020+1`
`=>(x+2024)/2023+(x+2024)/2022=(x+2024)/2021+(x+2024)/2020`
`=>(x+2024)/2023+(x+2024)/2022-(x+2024)/2021-(x+2024)/2020=0`
`=>(x+2024).(1/2023+1/2022-1/2021-1/2020)=0`
Vì `1/2023+1/2022-1/2021-1/2020` `\ne` `0`
`=> x+2024=0`
`=>x=-2024`
1) Tìm GTNN của biểu thức A= (|x| + 1)^10 + 2023
2) So sánh A và B:
A = 2022^2022 + 1 / 2022^2023 + 1 và B = 2022^2021 + 1 / 2022^2022 + 1
3) Thực hiện phép tính 1 cách hợp lí:
5^16 . 27^7/125^5 . 9^11
Do em ko biết viết phân số và mũ nên em viết hơi khó đọc mong mọi người thông cảm!😥
Cảm ơn mọi người giải giúp!
Đây nhé bé
Câu1
Vì \(\mid x \mid \geq 0 \Rightarrow \mid x \mid + 1 \geq 1\).
Do đó \(\left(\right. \mid x \mid + 1 \left.\right)^{10} \geq 1^{10} = 1\).
Suy ra:
\(A = \left(\right. \mid x \mid + 1 \left.\right)^{10} + 2023 \geq 1 + 2023 = 2024.\)
Dấu “=” chỉ xảy ra khi \(\mid x \mid = 0 \Leftrightarrow x = 0\).
\(\Rightarrow\) Giá trị nhỏ nhất của \(A\) là \(\boxed{2024}\), đạt tại \(x = 0\).
Câu 2 ( câu này kiến thức nâng cao nhé em nên là khi em đọc lời giải sẽ có khó hiểu nhé )
Đặt \(n = 2022\). Khi đó:
\(A = \frac{n^{2022} + 1}{n^{2023} + 1} , B = \frac{n^{2021} + 1}{n^{2022} + 1} .\)
Xét tổng quát với \(a_{k} = \frac{n^{k} + 1}{n^{k + 1} + 1} , \left(\right. n > 1 \left.\right)\).
Ta gọi k là luỹ thừa của cơ số
\(a_{k} > a_{k - 1} \textrm{ }\textrm{ } \Longleftrightarrow \textrm{ }\textrm{ } \left(\right. n^{k} + 1 \left.\right)^{2} > \left(\right. n^{k + 1} + 1 \left.\right) \left(\right. n^{k - 1} + 1 \left.\right) .\)
Xét hiệu:
\(\left(\right.n^{k}+1\left.\right)^2-\left(\right.n^{k+1}+1\left.\right)\left(\right.n^{k-1}+1\left.\right)=-n^{k-1}\left(\right.n-1\left.\right)^2<0\)
Vậy \(a_{k} < a_{k - 1}\), tức dãy \(\left(\right. a_{k} \left.\right)\) giảm dần theo \(k\)
Do đó:
\(A = a_{2022} < a_{2021} = B .\)
\(\Rightarrow B>A\)
Câu3
Ta đổi : \(27 = 3^{3}\), \(9 = 3^{2}\), \(125 = 5^{3}\).
\(\frac{5^{16} \cdot \left(\right. 3^{3} \left.\right)^{7}}{\left(\right. 5^{3} \left.\right)^{5} \cdot \left(\right. 3^{2} \left.\right)^{11}} = \frac{5^{16} \cdot 3^{21}}{5^{15} \cdot 3^{22}} = 5^{16 - 15} \cdot 3^{21 - 22} = \frac{5}{3} .\)
Vậy kết quả bằng \(\frac{5}{3}\).
Câu 3:
\(\frac{5^{16}\cdot27^7}{125^5\cdot9^{11}}\)
\(=\frac{5^{16}\cdot\left(3^3\right)^7}{\left(5^3\right)^5\cdot\left(3^2\right)^{11}}=\frac{5^{16}\cdot3^{21}}{5^{15}\cdot3^{22}}\)
\(=\frac53\)
Câu 2:
\(2022A=\frac{2022^{2023}+2022}{2022^{2023}+1}=1+\frac{2021}{2022^{2023}+1}\)
\(2022B=\frac{2022^{2022}+2022}{2022^{2022}+1}=1+\frac{2021}{2022^{2022}+1}\)
Ta có: \(2022^{2023}+1>2022^{2022}+1\)
=>\(\frac{2021}{2022^{2023}+1}<\frac{2021}{2022^{2022}+1}\)
=>\(\frac{2021}{2022^{2023}+1}+1<\frac{2021}{2022^{2022}+1}+1\)
=>2022A<2022B
=>A<B
Câu 1:
\(\left|x\right|\ge0\forall x\)
=>\(\left|x\right|+1\ge1\forall x\)
=>\(\left(\left|x\right|+1\right)^{10}\ge1^{10}=1\forall x\)
=>\(\left(\left|x\right|+1\right)^{10}+2023\ge1+2023=2024\forall x\)
Dấu '=' xảy ra khi x=0
Bài 2:
A = \(\frac{2022^{2022}+1}{2022^{2023}+1}\)
A = \(\frac{2022^{2022}+1}{2022^{2023}+1}\) < \(\frac{2022^{2022}+1+2021}{2022^{2023}+1+2021}\)
A < \(\frac{2022^{2022}+\left(1+2021\right)}{2022^{2023}+\left(1+2021\right)}\)
A < \(\frac{2022^{2022}+2022}{2022^{2023}+2022}\)
A < \(\) \(\frac{2022.\left(2022^{2021}+1\right)}{2022.\left(2022^{2022}+1\right)}\)
A < \(\frac{2022^{2021}+1}{2022^{2022}+1}\) = B
Vậy A < B
(X+1)+(x+2)+(x+3)+.....+(x+2022)=2023
=>2022x+2022*2023/2=2023
=>2022x=-2043230
=>x=-1010,5
a, cho x, y là 2 số thoả mãn (2x - y + 7)\(^{2022}\) + |x - 1|\(^{2023}\) ≤ 0. Tính giá trị của biểu thức: P = x\(^{2023}\) + (y - 10)\(^{2023}\)
b, Tìm số tự nhiên x, y biết 25 - y\(^2\) = 8(x = 2023)\(^2\)
c, Tìm giá trị nhỏ nhất của biểu thức: P = (|x - 3| + 2)\(^2\) + |y + 3| + 2019
d, Tìm cặp số nguyên x, y biết: (2 - x)(x + 1) = |y + 1|
a: \(\left(2x-y+7\right)^{2022}>=0\forall x,y\)
\(\left|x-1\right|^{2023}>=0\forall x\)
=>\(\left(2x-y+7\right)^{2022}+\left|x-1\right|^{2023}>=0\forall x,y\)
mà \(\left(2x-y+7\right)^{2022}+\left|x-1\right|^{2023}< =0\forall x,y\)
nên \(\left(2x-y+7\right)^{2022}+\left|x-1\right|^{2023}=0\)
=>\(\left\{{}\begin{matrix}2x-y+7=0\\x-1=0\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=1\\y=2x+7=9\end{matrix}\right.\)
\(P=x^{2023}+\left(y-10\right)^{2023}\)
\(=1^{2023}+\left(9-10\right)^{2023}\)
=1-1
=0
c: \(\left|x-3\right|>=0\forall x\)
=>\(\left|x-3\right|+2>=2\forall x\)
=>\(\left(\left|x-3\right|+2\right)^2>=4\forall x\)
mà \(\left|y+3\right|>=0\forall y\)
nên \(\left(\left|x-3\right|+2\right)^2+\left|y+3\right|>=4\forall x,y\)
=>\(P=\left(\left|x-3\right|+2\right)^2+\left|y-3\right|+2019>=4+2019=2023\forall x,y\)
Dấu '=' xảy ra khi x-3=0 và y-3=0
=>x=3 và y=3