Question

4x^2+(x-1)^2-(2x+1)^2=0

Answer 1

`4x^2 + ( x - 1 )^2 - ( 2x + 1 )^2 = 0`

`<=> 4x^2 + x^2 - 2x + 1 - 4x^2 - 4x - 1 = 0`

`<=> x^2 - 6x = 0`

`<=> x ( x - 6 ) = 0`

`<=>` $\left[\begin{matrix} x= 0\\ x - 6 =0\end{matrix}\right.$

`<=>` $\left[\begin{matrix} x= 0\\ x =6\end{matrix}\right.$

Vậy `S = { 0 ; 6 }`

Answer 2

\(\Leftrightarrow4x^2+\left(x^2-2x+1\right)-\left(4x^2+4x+1\right)=0\)

\(\Leftrightarrow4x^2+x^2+2x-1-4x^2-4x-1=0\)

\(\Leftrightarrow x^2-2x-2=0\) (ko tính đc)