Condition for pair of straight lines for equation
\[
Ax^2 + 2Hxy + By^2 + 2Gx + 2Fy + C = 0
\]
is
\[
\Delta = \begin{vmatrix} A & H & G \\ H & B & F \\ G & F & C \end{vmatrix} = 0.
\]
Substitute \(A=2, H=\frac{3}{2}, B=-2, G=-\frac{5}{2}, F=f, C=-3\).
Solve determinant equation for \(f\), resulting in \(f = \frac{5}{2}\).