Firstly, this is a bad way to solve equations:
inv(A)*b
You should read the inv documentation to know why, and what the better alternatives are (hint: mldivide).
Secondly, this is likely a bad way to use MATLAB:
[m1,m2,m3,m4]' = ...
Why bother? The name MATLAB comes from "MATrix LABoratory", not from "Let split the data up into lots of separate variables and make the code slow and complex". MATLAB works very efficiently with matrices, why do you want to split your data into hard-to-use separate variables?
Learn to use matrices/arrays and indexing, and then you will learn how to write neat, simple, efficient MATLAB code. To make code simpler and more efficient always keep data together as much as possible, rather than splitting it apart.
Putting data into numbered variables is also a very bad idea, as it inevitably leads beginners to writing slow, buggy code using bad code practices. Read this to know more:
