Bài 2:
a)$|2x-1|=3$
⇒$2x-1=3$ hoặc $2x-1=-3$
TH1:$2x-1=3$ TH2:$2x-1=-3$
⇒$2x=3+1$ ⇒$2x=-3+1$
⇒$2x=4$ ⇒$2x=-2$
⇒$x=4÷2$ ⇒$x=(-2)÷2$
⇒$x=2$ ⇒$x=-1$
Vậy $x$$∈${$-1,2$}
b)$|x-\dfrac{1}{2}$|$=$$\dfrac{3}{4}$
⇒$x-\dfrac{1}{2}$$=$$\dfrac{3}{4}$ hoặc $x-\dfrac{1}{2}$$=$$\dfrac{-3}{4}$
TH1:$x-\dfrac{1}{2}$$=$$\dfrac{3}{4}$
⇒$x=\dfrac{3}{4}$$+$$\dfrac{1}{2}$
⇒$x=\dfrac{3}{4}$$+$$\dfrac{2}{4}$
⇒$x=\dfrac{5}{4}$
TH2:$x-\dfrac{1}{2}$$=$$\dfrac{-3}{4}$
⇒$x=\dfrac{-3}{4}$$+$$\dfrac{1}{2}$
⇒$x=\dfrac{-3}{4}$$+$$\dfrac{2}{4}$
⇒$x=\dfrac{-1}{4}$
Vậy $x$$∈${$\dfrac{5}{4}$$,$$\dfrac{-1}{4}$}
Chúc bạn hok tốt!!!
