On shifting the origin to a particular point, the equation $x^2+y^2-4x-6y-12=0$ transforms to X² + Y² = K. Then K =

$\begin{array}{l}\text{ new origin }=\left(\frac{-g}{a},\frac{-f}{b}\right)=(2,3)\\ \Rightarrow x=X+h,y=Y+k\Rightarrow x=X+2,y=Y+3\\ Transformed equation is {(X+2)}^2+{(Y+3)}^2-4(X+2)-6(Y+3)-12=0\\ \Rightarrow X^2+Y^2-25=0\end{array}$