The document discusses the Gaussian elimination method for solving systems of equations. It provides an example problem involving determining the number of fertilizer bags needed to attain certain mineral requirements in a garden. The problem sets up variables and equations for the number of each type of fertilizer bag, puts them in an augmented matrix, performs row operations to put the matrix in row echelon form, and solves for the values of the variables which indicate the number of bags of each fertilizer needed. The solution is that the garden requires 1 bag of fertilizer A, 2 bags of fertilizer B, and 3 bags of fertilizer C.