Question:
Find the solution set of the in equation $|2 x-3|<1$.
Solution:
$|2 x-3|<1$
Square both sides
$\Rightarrow(2 x-3)^{2}<1^{2}$
$\Rightarrow 4 x^{2}-12 x+9<1$
$\Rightarrow 4 x^{2}-12 x+8<0$
Divide throughout by 4
$\Rightarrow x^{2}-3 x+2<0$
$\Rightarrow x^{2}-2 x-x+2<0$
$\Rightarrow x(x-2)-1(x-2)<0$
$\Rightarrow(x-1)(x-2)<0$
Observe that when $x$ is greater than $2(x-1)(x-2)$ is positive
And for each root the sign changes hence
We want less than 0 that is negative part
Hence $x$ should be between 1 and 2 for $(x-1)(x-2)$ to be negative
Hence $x \in(1,2)$
Hence the solution set of $|2 x-3|<1$ is $(1,2)$