Question

 

Answer 1

a, `<=> x - 3 = +-2^2`

`=> x - 3 = 2`

     `x - 3 = -2`

`=> x = 5`

     `x = 1`.

`b, (x-1)/(2x+1) < 1/2`

`-> (x-1)/(2x+1) - 1/2 < 0`

`=> 4x + 2 > 0`

`=> 2(x+1) > 0`

`=> x > -1`.

Answer 2

a: (x-3)²=4

b: \(\dfrac{x-1}{2x+1}< \dfrac{1}{2}\)

nên \(\dfrac{2\left(x-1\right)-2x-1}{2\left(2x+1\right)}< 0\)

=>2(2x+1)>0

=>2x+1>0

hay x>-1/2

Answer 3

a) \(\Leftrightarrow\left[{}\begin{matrix}x-3=2\\x-3=-2\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}x=5\\x=1\end{matrix}\right.\)