6.
已知两圆\(C\)\({\,\!}_{1}\):\(x\)\({\,\!}^{2}+\)\(y\)\({\,\!}^{2}-2\)\(x\)\(-6\)\(y\)\(-1=0\)和\(C\)\({\,\!}_{2}\):\(x\)\({\,\!}^{2}+\)\(y\)\({\,\!}^{2}-10\)\(x\)\(-12\)\(y\)\(+45=0\).
\((1)\)求证:圆\(C\)\({\,\!}_{1}\)和圆\(C\)\({\,\!}_{2}\)相交;
\((2)\)求圆\(C\)\({\,\!}_{1}\)和圆\(C\)\({\,\!}_{2}\)的公共弦所在直线的方程和公共弦长.