Tính C = \(13x^5-3y^3+2017\) tại x, y thỏa \(\left|x-1\right|+\left(y+2\right)^{2016}=0\)
cho các số x,y thỏa mãn đẳng thức \(3x^2+3y^2+4xy+2x-2y+2=0\\ \)
tính giá trị biểu thức M=\(\left(x+y\right)^{2016}+\left(x+2\right)^{2017}+\left(y-1\right)^{2018}\)
Ta có: \(3x^2+3y^2+4xy+2x-2y+2=0\)
\(\Leftrightarrow x^2+2x+1+y^2-2y+1+2x^2+4xy+2y^2=0\)
\(\Leftrightarrow\left(x+1\right)^2+\left(y-1\right)^2+2\left(x^2+2xy+y^2\right)=0\)
\(\Leftrightarrow\left(x+1\right)^2+\left(y-1\right)^2+2\left(x+y\right)^2=0\)
Ta có: \(\left(x+1\right)^2\ge0\forall x\)
\(\left(y-1\right)^2\ge0\forall y\)
\(2\left(x+y\right)^2\ge0\forall x,y\)
Do đó: \(\left(x+1\right)^2+\left(y-1\right)^2+2\left(x+y\right)^2\ge0\forall x,y\)
Dấu '=' xảy ra khi
\(\left\{{}\begin{matrix}x+1=0\\y-1=0\\x+y=0\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=-1\\y=1\\-1+1=0\left(đúng\right)\end{matrix}\right.\)
Thay x=-1 và y=1 vào biểu thức \(M=\left(x+y\right)^{2016}+\left(x+2\right)^{2017}+\left(y-1\right)^{2018}\), ta được:
\(M=\left(-1+1\right)^{2016}+\left(-1+2\right)^{2017}+\left(1-1\right)^{2018}\)
\(=0^{2016}+1^{2017}+0^{2018}=1\)
Vậy: M=1
Tính \(2x^5-5y^3+2017\)tại y thỏa mãn \(\left|x-1\right|+\left(y+2\right)^{2016}=0\)
\(\left|x-1\right|+\left(y+2\right)^{2016}=0\)
Ta thấy: \(\hept{\begin{cases}\left|x-1\right|\ge0\\\left(y+2\right)^{2016}\ge0\end{cases}}\)
\(\Rightarrow\left|x-1\right|+\left(y+2\right)^{2016}\ge0\)
\(\Rightarrow\hept{\begin{cases}\left|x-1\right|=0\\\left(y+2\right)^{2016}=0\end{cases}}\)\(\Rightarrow\hept{\begin{cases}x=1\\y=-2\end{cases}}\)
\(\Rightarrow A=2x^5-5y^3+2017=2\cdot1^5-5\cdot\left(-2\right)^3+2017=2059\)
\(C=2x-2y+13x^3y^2\left(x-y\right)+15\left(y^2x-x^2y\right)+\left(\dfrac{2015}{2016}\right)^0bitx-y=0\)
mong các bạn giúp minh
\(C=2\left(x-y\right)+13x^3y^2\left(x-y\right)-15xy\left(x-y\right)+1=1\)
Vậy C=1
\(C=2x-2y+13x^3y^2\left(x-y\right)+15\left(y^2x-x^2y\right)+\left(\dfrac{2015}{2016}\right)^0\)
\(C=2\left(x+y\right)+13x^3y^2\left(x-y\right)+15xy\left(x-y\right)+1\)
Mà x - y = 0 (bài cho)
\(\Rightarrow C=2.0+13x^3y^2.0+15xy.0+1\)
\(C=1\)
Vậy C=1
Tính B = \(13x^7-5y^3+2022\) tại x,y thỏa mãn: \(\left|x-1\right|+\left(y+2\right)^{2022}=0\)
\(\left|x-1\right|+\left(y+2\right)^{2022}=0\\ \Rightarrow\left\{{}\begin{matrix}\left|x-1\right|=0\\\left(y+2\right)^{2022}=0\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}x-1=0\\y+2=0\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}x=1\\y=-2\end{matrix}\right.\\ \Rightarrow B=13.1-5\left(-8\right)+2022=13+40+2022=2075\)
|x-1|+(y+2)2022=0
Do |x-1| và (y+2)2022 đều ≥0⇒\(\left\{{}\begin{matrix}x-1=0\\y+2=0\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}x=1\\y=-2\end{matrix}\right.\)
⇒B=13.(1)7-5.(-2)3+2022=13+40+2022=2075
\(C=2x-2y+13x^3y^2\left(x-y\right)+15\left(y^2x-x^2y\right)+\left(\frac{2015}{2016}\right)^0\)
\(C = 2.(x-y)+13x^3y^2.(x-y)+15.xy.\)
\((y-x) +1\)
\(C = 2.( x- y )+13x^3y^2.(x-y)-15.xy.\)
\(( x - y )+1\)
\(C = (x - y)(2 + 13x^3y^2 - 15 ) +1\)
\(C =(x- y)(13x^3y^2 - 13 )+ 1\)
Tính: \(C=2x-2y+13x^3y^2.\left(x-y\right)+15\left(y^2x-x^2y\right)+\left(\dfrac{2015}{2016}\right)^0\)
biết x - y = 0
Ta có:
\(C=2\left(x-y\right)+13x^3y^2\left(x-y\right)-15xy\left(x-y\right)+1\)
=\(0+0+0+1=1\)
\(C=2x-2y+13x^3y^2\left(x-y\right)+15\left(y^2x-x^2y\right)+\left(\dfrac{2015}{2016}\right)^0\)
\(=2\left(x-y\right)+13x^3y^2\left(x-y\right)-15xy\left(x-y\right)\)
\(=0+0+1=1\)
~^~
Cho x,y,z thỏa mãn đồng thời: \(3x-2y-2\sqrt{y+2012}+1=0\); \(3y-2z-2\sqrt{z-2013}+1=0\);\(3z-2x-2\sqrt{x-2}-2=0\)Tính \(C=\left(x-4\right)^{2016}+\left(y+2012\right)^{2017}+\left(z-2013\right)^{2008}\)
a) Cho x,y thỏa mãn đẳng thức \(\left(x+\sqrt{x^2+2016}\right)\left(y+\sqrt{y^2+2016}\right)=2016\).Tính x+y
b) Cho x,y thỏa mãn đẳng thức\(\left(\sqrt{x^2+2017}-x\right)\left(\sqrt{y^2+2017}-y\right)=2017\).Tính x+y
Tính giá trị của biểu thức sau:
C = \(2x-2y+13x^3y^2\left(x-y\right)+15\left(y^2x-x^2y\right)+\left(\dfrac{2015}{2016}\right)^0\), biết \(x-y=0\)
Ta có:\(C=2\left(x-y\right)+13x^3y^2\left(x-y\right)+15xy\left(y-x\right)+1\)Thế \(x-y=0\) vào C ta được:
\(C=0+0+0+1\)
C = 0