Related Post: X 1 )( X2 3x 4 X 1 3 X 4 2 X 1 3x 4x 2 X 1 X2 4x 3 X 1 X 2 X 3 X 4 10 3 1 X 2 X 3 X 4 Series Formula X 1 )( X 3 )( X 2 4x 5 X 1 X 2 Y 3 X 4 3 1 X 2 X 3 X 4 Series X 1 X 2 X 3 X 4 5x