This material is covered in chapter 0, which I do not know if we will cover by the end of the year. I cannot think of a type of system where a solution can only be obtained from this method, so I'm hesitant to learn it if we will always be allowed to pick which method to use when solving a non-homogeneous system. More generally my question is, even if we do not cover it in class, how marginal will the value of this method be compared to undetermined coefficients or variation of parameters, on the final or future courses? 