Least Squares Pure Imaginary Solution and Real Solution of the Quaternion Matrix Equation<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M1"><mml:mrow><mml:mi>A</mml:mi><mml:mi>X</mml:mi><mml:mi>B</mml:mi><mml:mo>+</mml:mo><mml:mi>C</mml:mi><mml:mi>X</mml:mi><mml:mi>D</mml:mi><mml:mo>=</mml:mo><mml:mi>E</mml:mi></mml:mrow></mml:math>with the Least Norm
Journal of applied mathematics