Question

Tìm x biết : 4x²-4x-1=0

Answer 1

\(\left(2x-1\right)^2=0\)

\(2x-1=0\Leftrightarrow x=\dfrac{1}{2}\)

Answer 2

x ∈ N*

Answer 3

\(\Rightarrow\left(4x^2-4x+1\right)-2=0\\ \Rightarrow\left(2x-1\right)^2=2\\ \Rightarrow\left[{}\begin{matrix}2x-1=\sqrt{2}\\2x-1=-\sqrt{2}\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=\dfrac{\sqrt{2}+1}{2}\\x=\dfrac{1-\sqrt{2}}{2}\end{matrix}\right.\)