Ta có: \(\left\{{}\begin{matrix}\left(2x-3y\right)^{2018}\ge0\forall x,y\\\left(3y-4z\right)^{2020}\ge0\forall y,z\\\left|2x+3y-z-63\right|\ge0\forall x,y,z\end{matrix}\right.\)

\(\Rightarrow\left(2x-3y\right)^{2018}+\left(3y-4z\right)^{2020}+\left|2x+3y-z-63\right|\ge0\forall x,y,z\)

Mà: \(\left(2x-3y\right)^{2018}+\left(3y-4z\right)^{2020}+\left|2x+3y-z-63\right|=0\)

nên: \(\left\{{}\begin{matrix}2x-3y=0\\3y-4z=0\\2x+3y-z-63=0\end{matrix}\right.\) \(\Rightarrow\left\{{}\begin{matrix}2x=3y\\3y=4z\\z=2x+3y-63\end{matrix}\right.\)

\(\Rightarrow\left\{{}\begin{matrix}2x=4z\\3y=4z\\z=4z+4z-63\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}x=4z:2\\y=4z:3\\z=8z-63\end{matrix}\right.\)

\(\Rightarrow\left\{{}\begin{matrix}x=2z\\y=4z:3\\-7z=-63\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}x=2\cdot9=18\\y=4\cdot9:3=12\\z=9\end{matrix}\right.\)

Vậy \(x=18;y=12;z=9\).

$Toru$

Băng Băng 2k6 giúp vs

Có:

\(\left|2x-27\right|^{2011}\ge0\forall x\)

\(\left(3y+10\right)^{2012}\ge0\forall y\)

\(\Rightarrow\left|2x-27\right|^{2011}+\left(3y+10\right)^{2012}\ge0\forall x;y\)

\(\Rightarrow\left|2x-27\right|^{2011}+\left(3y+10\right)^{2012}=0\)

\(\Leftrightarrow\left\{{}\begin{matrix}2x-27=0\\3y+10=0\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=\dfrac{27}{2}\\y=-\dfrac{10}{3}\end{matrix}\right.\)

Ta có : \(\left|2x-27\right|\ge0\forall x\Rightarrow\left|2x-27\right|^{2019}\ge0\forall x\)

\(\left(3x+10\right)^2\ge0\forall x\Rightarrow\left[\left(3x+10\right)^2\right]^{1009}=\left(3y+10\right)^{2018}\ge0\forall x\)

\(\Rightarrow\left|2x-27\right|^{2019}+\left(3y+10\right)^{2018}\ge0\forall x\)

Dấu " = " xảy ra \(\Leftrightarrow\left|2x-27\right|=\left(3y+10\right)=0\)

\(\Leftrightarrow\left\{{}\begin{matrix}x=\frac{27}{2}\\y=-\frac{10}{3}\end{matrix}\right.\)

Vì \(\left\{{}\begin{matrix}\left|2x-27\right|^{2011}\text{≥0,∀x}\\\left(3y+10\right)^{2012}\text{≥0,∀y}\end{matrix}\right.\)

⇒ \(\left|2x-27\right|^{2011}+\left(3y+10\right)^{2012}\text{≥0,∀x},y\)

Dấu "=" ⇔ \(\left\{{}\begin{matrix}2x-27=0\\3y+10=0\end{matrix}\right.\)

⇒ \(\left\{{}\begin{matrix}x=\dfrac{27}{2}\\y=-\dfrac{10}{3}\end{matrix}\right.\)

Vậy ...

Ta có \(\hept{\begin{cases}\left|2x-27\right|^{2011}\ge0\forall x\\\left(3y+10\right)^{2022}\ge0\forall y\end{cases}}\Rightarrow\left|2x-27\right|^{2011}+\left(3y+10\right)^{2022}\ge0\forall x;y\)

Dấu "=" xảy ra <=> \(\hept{\begin{cases}2x-27=0\\3y+10=0\end{cases}}\Rightarrow\hept{\begin{cases}x=\frac{27}{2}\\y=-\frac{10}{3}\end{cases}}\)

Vậy x = 27/2 ; y = -10/3 là giá trị cần tìm

ta có |2x-27| > hoặc = 0=> |2x-27|^2011> hoặc = 0

(3y+10)^2012> hoặc 0 mà |2x-27|^2011+(3y+10)^2012=0 

=>2x-27=0 hoặc 3y+10=0=>2x=27 hoặc 3y=-10

=>x=13,5 hoặc x=-10/3

vậy .............................

\(\left|2x+27\right|^{2011}+\left(3y+10\right)^{2012}=0\)

\(\hept{\begin{cases}\left|2x-27\right|^{2011}\ge0\forall x\\\left(3y+10\right)^{2012}\ge0\forall y\end{cases}}\Rightarrow\left|2x-27\right|^{2011}+\left(3y+10\right)^{2012}\ge0\forall x;y\)

Dấu ''='' xảy ra \(x=\frac{27}{2};y=-\frac{10}{3}\)

2001X2000-2/1999+1999x2001

Ta thấy \(\frac{2019}{3}.|x-3y|\ge0\forall x,y\)

            \(|2x-2|\ge0\forall x\)

\(\Rightarrow\frac{7}{4}-\frac{2019}{3}.|x-3y|+|2x-2|+2020\ge\frac{1}{2}-0+2020\)

Hay \(C\ge\frac{4041}{2}\)

Dấu "=" xảy ra \(\Leftrightarrow\hept{\begin{cases}x-3y=0\\2x-2=0\end{cases}}\)

                       \(\Leftrightarrow\hept{\begin{cases}y=\frac{1}{3}\\x=1\end{cases}}\)

Vậy Min \(C=\frac{4041}{2}\)\(\Leftrightarrow\hept{\begin{cases}y=\frac{1}{3}\\x=1\end{cases}}\)