Question

Tìm x biết:

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

Answer 1

(4x-1)²-(x²+2x+1)=0

(4x-1)²-(x+1)²=0

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

(3x-2)5x=0

x=0 hoặc 3x-2=0=>x=2/3

Answer 2

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

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

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

\(\Rightarrow\left(4x-1-x-1\right)\left(4x-1+x+1\right)=0\)

\(\Rightarrow\left(3x-2\right).5x=0\)

\(\Rightarrow\left[{}\begin{matrix}x=0\\x=\dfrac{2}{3}\end{matrix}\right.\)