Tìm x biết |x - 2018/2019| + |x - 2019/2020| = 0
Tìm x,y biết x^2018+y^2018=x^2019+y^2019=x^2020+y^2020.
Cho a+b+c=2019, 1/a + 1/b+1/c=1/2019. Tính 1/a^2019+1/b^2019+1/c^2019
Tìm x,y biết x^2-xy=6x-5y-8.
Giúp mk với, mk vã lắm rồi :-( :-(
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là sẽ tìm được nghiệm nguyên củaTìm x thuộc Z,biết
A)4.(x mũ 2 +1)=0
B) - 2018.(x + 2019)= 0 mũ 2020
a ) 4 . ( x2 + 1 ) = 0
x2 + 1 = 0 : 4
x2 + 1 = 0
x2 = 0 - 1
x2 = - 1
x2 = - 12 => x = - 1
Vậy x = - 1
b ) - 2018 . ( X + 2019 ) = 02020
- 2018 . ( x + 2019 ) = 0
x + 2019 = 0 : ( - 2018 )
x + 2019 = 0
x = 0 - 2019
x = - 2019
Vậy x = - 2019
B=x^2020 -2019 x^2019 - x^2018 - 2019 x^2017 - ...-2019x-2020 với x=2020
(x+2018)^2020 - (x+2018)^2019 = 0
\(\left(x+2018\right)^{2020}-\left(x+2018\right)^{2019}=0\)
\(\Leftrightarrow\) \(\left(x+2018\right)^{2019}\left(x+2018-1\right)=0\)
\(\Leftrightarrow\) \(\left(x+2018\right)^{2019}\left(x+2017\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}\left(x+2018\right)^{2019}=0\\x+2017=0\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x=-2018\\x=-2017\end{matrix}\right.\)
\(\left(x+2018\right)^{2020}-\left(x+2018\right)^{2019}=0\\ \Leftrightarrow\left(x+2018\right)^{2019}\left[\left(x+2018\right)^2-1\right]=0\\ \Leftrightarrow\left(x+2018\right)^{2019}\left(x+2017\right)\left(x+2019\right)=0\\ \Rightarrow\left[{}\begin{matrix}x+2018=0\\x+2017=0\\x+2019=0\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=-2018\\x=-2017\\x=-2019\end{matrix}\right.\)
(x+2018)^2020 - (x+2018)^2019 = 0
\(\Leftrightarrow\left(x+2018\right)^{2019}\left(x+2018-1\right)=0\)
\(\Leftrightarrow\left(x+2017\right)\left(x+2018\right)^{2019}=0\)
\(\Leftrightarrow\left[{}\begin{matrix}\left(x+2018\right)^{2019}=0\\x+2017=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=-2018\\x=-2017\end{matrix}\right.\) ( TM )
Tìm x ,y, z biết: x-y=2018; y-z = -2019; z+x= 2020
. Tìm x ,y, z biết: x-y=2018; y-z = -2019; z+x= 2020
tìm x,y thuộc Z biết
a)25-y2=8(x-2019)2
b)|2018-x|+|2019-x|+|2020-x|=2
a) Ta có:\(8\left(x-2019\right)^2⋮8\Rightarrow25-y^2⋮8\)\(\left(1\right)\)
Mặt khác: \(8\left(x-2019\right)^2\ge0\Rightarrow25-y^2\ge0\)\(\left(2\right)\)
Từ\(\left(1\right),\left(2\right)\)ta có: \(y^2=1;9;25\)
Xét:\(y^2=1\Rightarrow8\left(x-2019\right)^2=24\Rightarrow\left(x-2019\right)^2=3\left(ktm\right)\)
\(y^2=9\Rightarrow8\left(x-2019\right)^2=16\Rightarrow\left(x-2019\right)^2=2\left(ktm\right)\)
\(y^2=25\Rightarrow8\left(x-2019\right)^2=0\Rightarrow\left(x-2019\right)^2=0\Rightarrow x-2019=0\Rightarrow x=2019\left(tm\right)\)
Vậy \(y=5;x=2019\)
\(y=-5;x=2019\)
A= x^5 - 2019 x^4 + 2019 x^3 - 2019 x^2 +2019 x -2020 tại x = 2018