4 Equations in Matrix Algebra

may be written

i.e.,

Also if we have the following pair of equations:

then

where . This is very convenient notation compared with direct substitution. The Mx structural equations are written in this general form, i.e.,

Real variables (y) = Matrix hypothetical variables.To show the simplicity of the matrix notation, consider the following equations:

Then we have

Similarly, in matrix notation, we have , where

and

or