2 câu trả lời
`|2x + sqrt{1/4}| - 25% = 0,5`
`|2x + 1/2| - 0,25 = 0,5`
`|2x + 1/2| = 0,5 + 0,25`
`|2x + 1/2| = 0,75`
`=> 2x + 1/2 in {0,75; -0,75}`
`=> 2x in {1/4; -5/4}`
`=> x in {1/8; -5/8}`
Vậy `x in {1/8; -5/8}`
$\text{| 2x + $\sqrt{\dfrac{1}{4} }$ | - 25% = 0,5 }$
$\text{| 2x + $\sqrt{\dfrac{1}{4} }$ | = 0,5 + 25% }$
$\text{| 2x + $\sqrt{\dfrac{1}{4} }$ | = 0,75 }$
$\text{| 2x + 0,5 | = 0,75 }$
$\text{→ | 2x + 0,5 | = | 0,75 | = | -0,75 | }$
$\left[\begin{matrix} 2x + 0,5=0,75\\ 2x + 0,5 = -0,75\end{matrix}\right.$
$\left[\begin{matrix} 2x =0,25\\ 2x = -1,25\end{matrix}\right.$
$\left[\begin{matrix} x =0,125\\ 2x = -0,625\end{matrix}\right.$
$\text{→ Vậy x ∈ { 0,125 ; -0,625 } }$
