Question

tìm x biết

x²-x+1/4=0

Answer 1

\(x^2-x+\dfrac{1}{4}=0\)

\(\Leftrightarrow x^2-2.x.\dfrac{1}{2}+\left(\dfrac{1}{2}\right)^2=0\)

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

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

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

Vậy \(x=\dfrac{1}{2}\)

Answer 2

<=> \(x^2 - 2\dfrac{1}{2}x + \dfrac{1}{2^2}\) = 0 ( hằng đẳng thức số 2)

<=> \(( x - \dfrac{1}{2})^2\) = 0 <=> \(x - \dfrac{1}{2} = 0\) <=> x = \(\dfrac{1}{2}\)

Vậy pt có nghiệm là x = 1/2