Solving system of linear equations with transpose matrix

Dears,  I have a system of linear equation A*X=B   where A matrix 607x400  & X vector  400x1 and B vector 400x1

where A not square matrix. To sove,  I do

(A^T)*A*X=(A^T)*B,

Let   D= (A^T)*A        D  square matrix

then

D*X=(A^T)*B,

the solution is

X= (D^-1)*(A^T)*B.

could any one help me to do this by maple and cut the resluts in groups every group contains 100 element.

 Amr