Concept:
If a point \((x,y)\) is equidistant from two lines
\[
a_1x+b_1y+c_1=0
\]
and
\[
a_2x+b_2y+c_2=0,
\]
then
\[
\frac{|a_1x+b_1y+c_1|}
{\sqrt{a_1^2+b_1^2}}
=
\frac{|a_2x+b_2y+c_2|}
{\sqrt{a_2^2+b_2^2}}.
\]
Squaring both sides gives the required locus.
Step 1: Write the distance condition.
Given lines
\[
L_1:2x+3y+1=0,
\]
\[
L_2:3x-2y+1=0.
\]
Since
\[
\sqrt{2^2+3^2}
=
\sqrt{13}
\]
and
\[
\sqrt{3^2+(-2)^2}
=
\sqrt{13},
\]
the condition of equal distances becomes
\[
|2x+3y+1|
=
|3x-2y+1|.
\]
Step 2: Square both sides.
\[
(2x+3y+1)^2
=
(3x-2y+1)^2.
\]
Using
\[
a^2-b^2=(a-b)(a+b),
\]
we get
\[
[(2x+3y+1)-(3x-2y+1)]
[(2x+3y+1)+(3x-2y+1)]
=0.
\]
\[
(-x+5y)(5x+y+2)=0.
\]
Step 3: Expand the product.
\[
(-x+5y)(5x+y+2)=0.
\]
\[
-5x^2+24xy+5y^2-2x+10y=0.
\]
Multiplying throughout by \(-1\),
\[
5x^2-24xy-5y^2+2x-10y=0.
\]
Step 4: Write the final answer.
\[
\boxed{
5x^2-24xy-5y^2+2x-10y=0
}
\]