Bài 2 : Tìm x, biết : a) |2x-1|=3 b) |x – $\frac{1}{2}$ | = $\frac{3}{4}$ 03/09/2021 Bởi Charlie Bài 2 : Tìm x, biết : a) |2x-1|=3 b) |x – $\frac{1}{2}$ | = $\frac{3}{4}$
a)|2x-1|=3 TH1: TH2: 2x-1=3 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-1/2|=3/4 TH1: TH2: x-1/2=3/4 x-1/2=-3/4 =>x=3/4+1/2 =>x=(-3/4)+1/2 =>x=5/4 =>x=-1/4 Vậy x∈{-1/4;5/4} Chúc bạn hok tốt nha!! Bình luận
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$$∈${$\dfrac{5}{4}$$,$$\dfrac{-1}{4}$} Chúc bạn hok tốt!!! Bình luận
a)|2x-1|=3
TH1: TH2:
2x-1=3 2x-1=-3
=>2x=3+1 =>2x=(-3)+1
=> 2x=4 =>2x=-2
=> x=4:2 =>x=(-2):2
=>x=2 => x=-1
Vậy x∈{-1;2}
b)|x-1/2|=3/4
TH1: TH2:
x-1/2=3/4 x-1/2=-3/4
=>x=3/4+1/2 =>x=(-3/4)+1/2
=>x=5/4 =>x=-1/4
Vậy x∈{-1/4;5/4}
Chúc bạn hok tốt nha!!
Bài 2:
a)$|2x-1|=3$
⇒$2x-1=3$ hoặc $2x-1=-3$
TH1:$2x-1=3$ TH2:$2x-1=-3$
⇒$2x=3+1$ ⇒$2x=-3+1$
⇒$2x=4$ ⇒$2x=-2$
⇒$x=4÷2$ ⇒$x=(-2)÷2$
⇒$x=2$ ⇒$x=-1$
Vậy $x$$∈${$-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!!!