Vector Algebra

In quadrilateral \(A B C D, \mathbf{A B}=\mathbf{a}, \mathbf{B C}=\mathbf{b}\). \(\mathbf{D A}=\mathbf{a}-\mathbf{b}, M\) is the mid-point of \(B C\) and \(X\) is a point on DM such that, \(\mathbf{D X}=\frac{4}{5}\) DM.
Then, the points \(A, X\) and \(C\).