If the lines $2x-3y=5$ and $3x-4y=7$ are two diameters of a circle of radius 7, then the equation of the circle is

$\begin {array} {1 1} (1)\;x^2+y^2+2x-4y-47=0 & \quad (2)\;x^2+y^2=49 \\ (3)\;x^2+y^2-2x+2y-47=0 & \quad (4)\;x^2+y^2=17 \end {array}$

$(3)\;x^2+y^2-2x+2y-47=0$