Solving 3 Equations for 3 Unknowns Using a Matrix in Row Echelon Form

Equations remain valid if multiplied by constants or added to other valid equations. For that reason, rows of matrices can be multiplied by constants or added together. We use that idea to solve systems of three equations for 3 unknowns by getting a matrix into "row echelon form," in which all entries below the diagonal are zero. A matrix in considered to be in "reduced row echelon form" (not used in this video) if the diagonal elements are all equal to 1 and all elements below the diagonal are zeroes. There is a spoken error a little after 7:05 in which I call it reduced row echelon when it is actually just in row echelon form. #precalculus #rowechelon #maths