如图,在平面直角坐标系\(xOy\)中,直线\({{l}_{1}}:y=mx(m\ne 0)\)与直线\({{l}_{2}}:y=ax+b(a\ne 0)\)相交于点\(A(2,4)\),直线\({{l}_{2}}\)与\(x\)轴交于点\(B(6,0)\)
\((1)\)分别求直线\({{l}_{1}}\)和\({{l}_{2}}\)的表达式;
\((2)\)过动点\(P(0,n)\)且垂直于\(y\)轴的直线与\({{l}_{1}}\),\({{l}_{2}}\)的交点分别为\(C\),\(D\),当点\(C\)位于点\(D\)左方时,请直接写出\(n\)的取值范围.