4. Let the elementary row operations on a matrix of numbers be multiply a row by a nonzero scalar, add a row to another row, interchange two rows. (a) Matrices are labeled according to their "exc" (rows by columns) size. Use an Excel spread- sheet and the first two elementary row operations to reduce any A2x3 matrix of nonzero elements to reduced row echelon form. The only requirement is that once the candidate matrix is entered into the spreadsheet cells, your spreadsheet must reduce it to reduced row echelon form by a single keystroke. You may assume that the pivot locations are all nonzero for your program and that no interchange of rows is needed to reduce to row echelon form. On the other hand, if you devise a way using the logic commands of Excel to interchange two rows when conditions need it, you may program that elementary row operation as well. (b) Next, on a new tab of your spreadsheet, expand your work to reduce any matrix B of nonzero elements to reduced row echelon form, where B = B5x6. 4. Let the elementary row operations on a matrix of numbers be multiply a row by a nonzero scalar, add a row to another row, interchange two rows. (a) Matrices are labeled according to their "exc" (rows by columns) size. Use an Excel spread- sheet and the first two elementary row operations to reduce any A2x3 matrix of nonzero elements to reduced row echelon form. The only requirement is that once the candidate matrix is entered into the spreadsheet cells, your spreadsheet must reduce it to reduced row echelon form by a single keystroke. You may assume that the pivot locations are all nonzero for your program and that no interchange of rows is needed to reduce to row echelon form. On the other hand, if you devise a way using the logic commands of Excel to interchange two rows when conditions need it, you may program that elementary row operation as well. (b) Next, on a new tab of your spreadsheet, expand your work to reduce any matrix B of nonzero elements to reduced row echelon form, where B = B5x6