Solve each of the following in equations and represent the solution set on the number line.
$\left|\frac{2 x-1}{x-1}\right|<2, x \in \mathbf{R} .$
Given:
$\left|\frac{2 x-1}{x-1}\right|<2, x \in R$
$-2<\left|\frac{2 x-1}{x-1}\right|<2$
$\frac{2 x-1}{x-1}>-2$ and $\frac{2 x-1}{x-1}<2$
When,
$\frac{2 x-1}{x-1}>-2$
Adding 2 to both sides in the above equation
$\frac{2 x-1}{x-1}+2>-2+2$
$\frac{2 x-1+2(x-1)}{x-1}>0$
$\frac{2 x-1+2 x-2}{x-1}>0$
$\frac{4 x-3}{x-1}>0$
Signs of 4x – 3:
$4 x-3=0 \rightarrow x=\frac{3}{4}$
(Adding 3 to both sides and then dividing both sides by 4)
$4 x-3>0 \rightarrow x>\frac{3}{4}$
(Adding 3 to both sides and then dividing both sides by 4)
$4 x-3<0 \rightarrow x<\frac{3}{4}$
(Adding 3 to both sides and then dividing both sides by 4)
Signs of x – 1:
$x-1=0 \rightarrow x=1$ (Adding 1 to both the sides)
$x-1>0 \rightarrow x>1$ (Adding 1 to both the sides)
$x-1<0 \rightarrow x<1$ (Adding 1 to both the sides)
At $x=1, \frac{4 x-3}{x-1}$ is not defined.
Intervals that satisfy the required condition: > 0
$x<\frac{3}{4}$ or $x>1$
Now, when $\frac{2 x-1}{x-1}<2$
Subtracting 2 from both the sides
$\frac{2 x-1}{x-1}-2<2-2$
$\frac{2 x-1-2(x-1)}{x-1}<0$
$\frac{2 x-1-2 x+2)}{x-1}<0$
$\frac{1}{x-1}<0$
Signs of x – 1:
$x-1=0 \rightarrow x=1$ (Adding 1 on both the sides)
$x-1<0 \rightarrow x<1$ (Adding 1 on both the sides)
$x-1>0 \rightarrow x>1$ (Adding 1 on both the sides)
At $x=1, \frac{1}{x-1}$ is not defined
Interval which satisfy the required condition: < 0
x < 1
Now, combining the intervals:
$x<\frac{3}{4}$ or $x>1$ and $x<1$
Merging the overlapping intervals:
$x<\frac{3}{4}$
Therefore,
$x \in\left(-\infty, \frac{3}{4}\right)$