Question

Câu 31: 

b) Tìm x, y, z biết: \(4x^2-4x+9y^2-6y+16z^2-8z+3=0\)

Answer 1

\(4x^2-4x+9y^2-6y+16z^2-8z+3=0\) 

\(\left(4x^2-4x+1\right)+\left(9y^2-6y+1\right)+\left(16z^2-8y+1\right)=0\) 

\(\left(2x-1\right)^2+\left(3y-1\right)^2+\left(4z-1\right)^2=0\) 

\(=>\hept{\begin{cases}\left(2x-1\right)^2=0\\\left(3y-1\right)^2=0\\\left(4z-1\right)^2=0\end{cases}=>\hept{\begin{cases}2x-1=0\\3y-1=0\\4z-1=0\end{cases}=>\hept{\begin{cases}x=\frac{1}{2}\\y=\frac{1}{3}\\z=\frac{1}{4}\end{cases}}}}\)

Vậy...