|2x+1|=4
Suy ra:+2x+1=4\(\Rightarrow\)2x=3\(\Rightarrow\)x=\(\frac{3}{2}\)
+2x+1=-4\(\Rightarrow\)2x=-5\(\Rightarrow\)x=\(-\frac{5}{2}\)
Vậy x=\(\frac{3}{2}\);\(-\frac{5}{2}\)
\(\left|2x+1\right|=4\)
\(\Leftrightarrow\left|2x+1\right|=\pm4\)
\(\Leftrightarrow\left[\begin{array}{nghiempt}2x+1=4\\2x+1=-4\end{array}\right.\)
\(\Leftrightarrow\left[\begin{array}{nghiempt}2x=3\\2x=-5\end{array}\right.\)
\(\Leftrightarrow\left[\begin{array}{nghiempt}\frac{3}{2}\\-\frac{5}{2}\end{array}\right.\)
Vì / 2x +1/ = 4
suy ra 2x +1 = 4 hoặc 2x +1 = ( -4)
vậy ta sẽ có 2 trường hợp
TH 1 : 2x +1 = 4
2x = 4 - 1
2x = 3
x = 3 : 2
x = 1, 5 = \(\frac{3}{2}\)
TH 2 : 2x + 1 = ( -4 )
2x = ( -4 ) - 1
2x = ( -5 )
x = ( -5 ) :2
x = ( -2,5 ) = \(\frac{-5}{2}\)
Vậy x = \(\frac{3}{2}\)
hoặc \(\frac{-5}{2}\)