(2x - 1 )²⁰⁰⁸+(y - 2/5)²⁰⁰⁸ + |x + y - z | = 0

=> ( 2x - 1) ²⁰⁰⁸ =0                     => 2x - 1 =0                => 2x = 1                       => x = 1/2 

     ( y - 2/5 )²⁰⁰⁸ = 0                        y - 2/5 = 0                   y =2/5                           y = 2/5

     |x + y -z | = 0                             x + y - z = 0                x + 2/5 - z = 0                1/2 - 2/5  -z = 0 

=>x = 1/2              =>x = 1/2

    y = 2/5                  y = 2/5

    5/10 - 4/10 = z       z = 1/ 10

                                                                 Vậy x = 1/2 ; y = 2/5 : z = 1/10

( nhớ cho mk nha )

ta có: \(\left(2x-1\right)^{2008}\ge0\)

\(\left(y-\frac{2}{5}\right)^{2008}\ge0\)

\(\left|x+y-z\right|\ge0\)

\(\Rightarrow\left(2x-1\right)^{2008}+\left(y-\frac{2}{5}\right)^{2008}+\left|x+y-z\right|\ge0\)

để \(\left(2x-1\right)^{2008}+\left(y-\frac{2}{5}\right)^{2008}+\left|x+y-z\right|=0\)

\(\Rightarrow\left(2x-1\right)^{2008}=0\Rightarrow2x-1=0\Rightarrow x=\frac{1}{2}\)

\(\left(y-\frac{2}{5}\right)^{2008}=0\Rightarrow y-\frac{2}{5}=0\Rightarrow\frac{2}{5}\)

\(\left|x+y-z\right|=0\Rightarrow x+y-z=0\Rightarrow z=x+y\Rightarrow z=\frac{1}{2}+\frac{2}{5}=\frac{9}{10}\)

KL: x= 1/2; y= 2/5; z=9/10

( mk nghĩ nó còn có nhiều đáp số lắm, nhưng mk ko bít cách lm)

ta có: \(\left(\text{2x − 1}\right)^{2018}\) ≥ 0

\(\left(y-\frac{2}{5}\right)^{2018}\) ≥ 0

\(\left|x+y-z\right|\) ≥ 0

⇒ \(\left(\text{2x − 1 }\right)^{2018}\)+ \(\left(y-\frac{2}{5}\right)^{2018}\) +\(\left|\text{ x + y − z }\right|\) ≥ 0

để \(\left(\text{2x − 1}\right)^{2018}\) + \(\left(y-\frac{2}{5}\right)^{2018}\) + \(\left|\text{x + y − z}\right|\) = 0

⇒ \(\left(\text{2x − 1}\right)^{2018}\) = 0 ⇒ 2x − 1 = 0 ⇒ x = \(\frac{1}{2}\)

\(\left(y-\frac{2}{5}\right)^{2018}\) = 0 ⇒ y − \(\frac{2}{5}\) = 0⇒ \(\frac{2}{5}\)

\(\left|\text{x + y − z}\right|\) = 0 ⇒ x + y − z = 0 ⇒ z = x + y ⇒z = \(\frac{1}{2}\) + \(\frac{2}{5}\) = \(\frac{9}{10}\)

KL: x = \(\frac{1}{2}\); y = \(\frac{2}{5}\); z = \(\frac{9}{10}\)

( mình nghĩ nó còn có nhiều đáp số lắm, nhưng mình ko biết cách làm)

Chúc bạn học có hiệu quả!

a: =>|x-2009|=2009-x

=>x-2009<=0

=>x<=2009

b: =>2x-1=0 và y-2/5=0 và x+y-z=0

=>x=1/2 và y=2/5 và z=x+y=1/2+2/5=5/10+4/10=9/10

a)/x-2009/=2009-x

TH1:x-2009=2009-x=>x=2009

TH2:x-2009=-(2009-x)=>x-2009=x-2009 đúng với mọi x

b) (2x-1)^2008>=0

(y-2/5)^2008>=0

/x-y-z/>=0

=>2x-1=0

y-2/5=0

x-y-z=0(cái này dùng ngoặc nhọn)

=>x=1/2;y=2/5;z=1/10

\(a)\) \(2009-\left|x-2009\right|=x\)

\(\Leftrightarrow\)\(\left|x-2009\right|=2009-x\)

Ta có : \(\left|x-2009\right|\ge0\)

\(\Rightarrow\)\(2009-x\ge0\)

\(\Rightarrow\)\(x\le2009\)

\(\Leftrightarrow\)\(\orbr{\begin{cases}x-2009=2009-x\\x-2009=x-2009\end{cases}\Leftrightarrow\orbr{\begin{cases}x+x=2009+2009\\x=x\end{cases}}}\)

\(\Leftrightarrow\)\(\orbr{\begin{cases}2x=4018\\x=x\end{cases}\Leftrightarrow\orbr{\begin{cases}x=2009\\x=x\end{cases}}}\)

Vậy \(x=2009\)

Chúc bạn học tốt ~ 

(2x-1)²⁰⁰⁸ \(\ge\) 0 với mọi x

(y-2/5)²⁰⁰⁸ \(\ge\) 0 với mọi y

|x+y+z| \(\ge\) 0 với mọi x;y;z

=>(2x-1)²⁰⁰⁸+(y-2/5)²⁰⁰⁸+|x+y+z| \(\ge\) 0 với mọi x;y;z

Mà (2x-1)²⁰⁰⁸+(y-2/5)²⁰⁰⁸+|x+y+z| = 0 (theo đề)

=>(2x-1)²⁰⁰⁸+(y-2/5)²⁰⁰⁸=|x+y+z|=0

+)(2x-1)²⁰⁰⁸=0=>2x-1=0=>2x=1=>x=1/2

+)(y-2/5)²⁰⁰⁸=0=>y-2/5=0=>y=2/5

+)|x+y+z|=0=>x+y+z=0=>(1/2+2/5)+z=0=>9/10+z=0=>z=-/910

Vậy x=1/2;y=2/5;z=-9/10

Hoàng Phúc very PRO

Bài 1:

\(\left|x+\frac{1}{2}\right|+\left|x+\frac{1}{6}\right|+...+\left|x+\frac{1}{101}\right|=101x\)

Ta thấy:

\(VT\ge0\Rightarrow VP\ge0\Rightarrow101x\ge0\Rightarrow x\ge0\)

\(\Rightarrow\left(x+\frac{1}{2}\right)+\left(x+\frac{1}{6}\right)+...+\left(x+\frac{1}{101}\right)=101x\)

\(\Rightarrow\left(x+x+...+x\right)+\left(\frac{1}{2}+\frac{1}{6}+...+\frac{1}{101}\right)=0\)

\(\Rightarrow10x+\left(\frac{1}{1.2}+\frac{1}{2.3}+...+\frac{1}{10.11}\right)=0\)

\(\Rightarrow10x+\left(1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+...+\frac{1}{10}-\frac{1}{11}\right)=0\)

\(\Rightarrow10x+\left(1-\frac{1}{11}\right)=0\)

\(\Rightarrow10x+\frac{10}{11}=0\)

\(\Rightarrow10x=-\frac{10}{11}\Rightarrow x=-\frac{1}{11}\)(loại,vì x\(\ge\)0)

Bài 2:

Ta thấy: \(\begin{cases}\left(2x+1\right)^{2008}\ge0\\\left(y-\frac{2}{5}\right)^{2008}\ge0\\\left|x+y+z\right|\ge0\end{cases}\)

\(\Rightarrow\left(2x+1\right)^{2008}+\left(y-\frac{2}{5}\right)^{2008}+\left|x+y+z\right|\ge0\)

Mà \(\left(2x+1\right)^{2008}+\left(y-\frac{2}{5}\right)^{2008}+\left|x+y+z\right|=0\)

\(\left(2x+1\right)^{2008}+\left(y-\frac{2}{5}\right)^{2008}+\left|x+y+z\right|=0\)

\(\Rightarrow\begin{cases}\left(2x+1\right)^{2008}=0\\\left(y-\frac{2}{5}\right)^{2008}=0\\\left|x+y+z\right|=0\end{cases}\)\(\Rightarrow\begin{cases}2x+1=0\\y-\frac{2}{5}=0\\x+y+z=0\end{cases}\)

\(\Rightarrow\begin{cases}x=-\frac{1}{2}\\y=\frac{2}{5}\\x+y+z=0\end{cases}\)\(\Rightarrow\begin{cases}x=-\frac{1}{2}\\y=\frac{2}{5}\\-\frac{1}{2}+\frac{2}{5}+z=0\end{cases}\)

\(\Rightarrow\begin{cases}x=-\frac{1}{2}\\y=\frac{2}{5}\\-\frac{1}{10}=-z\end{cases}\)\(\Rightarrow\begin{cases}x=-\frac{1}{2}\\y=\frac{2}{5}\\z=\frac{1}{10}\end{cases}\)

\(\left(2x-1\right)^{2008}+\left(y-\dfrac{2}{5}\right)^{2008}+\left|x+y+z\right|=0\)

Nhận xét : \(\left\{{}\begin{matrix}\left(2x-1\right)^{2008}\ge0\forall x\\\left(y-\dfrac{2}{5}\right)^{2008}\ge0\forall y\\\left|x+y+z\right|\ge0\forall x,y,z\end{matrix}\right.\)

\(\Rightarrow\left\{{}\begin{matrix}\left(2x-1\right)^{2008}=0\\\left(y-\dfrac{2}{5}\right)^{2008}=0\\\left|x+y+z\right|=0\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=\dfrac{1}{2}\\y=\dfrac{2}{5}\\z=-\dfrac{9}{10}\end{matrix}\right.\)

\(\left(2x-1\right)^{2008}+\left(y-\dfrac{2}{5}\right)^{2008}+\left|x+y-z\right|\ge0\)

Dấu "=" xảy ra khi: \(\left\{{}\begin{matrix}x=\dfrac{1}{2}\\y=\dfrac{2}{5}\\z=\dfrac{9}{10}\end{matrix}\right.\)