3 The line \(A B\) has equation \(3 x + 2 y = 7\). The point \(C\) has coordinates \(( 2 , - 7 )\).
- Find the gradient of \(A B\).
- The line which passes through \(C\) and which is parallel to \(A B\) crosses the \(y\)-axis at the point \(D\). Find the \(y\)-coordinate of \(D\).
- The line with equation \(y = 1 - 4 x\) intersects the line \(A B\) at the point \(A\). Find the coordinates of \(A\).
- The point \(E\) has coordinates \(( 5 , k )\). Given that \(C E\) has length 5 , find the two possible values of the constant \(k\).