ng the matrix
<math display="inline" xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mi>ùêó</mi><annotation encoding="application/x-tex">\mathbf{X}</annotation></semantics></math>
as
<math display="inline" xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>ùêó</mi><mo mathvariant="bold">=</mo><mi>ùêê</mi><mi>ùêë</mi></mrow><annotation encoding="application/x-tex">\mathbf{X = Q R}</annotation></semantics></math>,
where
<math display="inline" xmlns="http://www.w3.or