CHAPTER 8.1. Matrices and Systems of Equations. Matrix - a streamlined technique for solving systems of linear equations that involves the use of a rectangular array of numbers. M rows. N columns. M x N. Order of Matrices. system. augmented matrix. coefficient matrix.
Matrices and Systems of Equations
M x N
1. Begin by writing the linear system and aligning the variables.
2. Next, use the coefficients and constant terms as the matrix entries. Include zeroes for each missing coefficients.
1. Interchange two rows.
2. Multiply a row by a nonzero constant.
3. Add a multiple of a row to another row.
Use back-substitution to find the solution
1. All rows consisting of zeroes occur at the bottom of the matrix.
2. For each row that does not consist of zeroes, the first nonzero entry is 1(called a leading 1).
3. For two successive (nonzero) rows, the leading 1 in the higher row is farther to the left than the leading 1 in the lower row.
Reduced row-echelon form- if every column that has a leading 1 has zeroes in every position above and below its leading 1.
Reduced row-echelon form
Switch row 1 with row 2
1. Write the augmented matrix of the system of linear equations.
2. Use elementary row operations to rewrite the augmented matrix in row-echelon form.
3. Write the system of linear equations corresponding to the matrix in row-echelon form and use back-substitution to find the solution.
Solve the system
inconsistent, no solution
Apply additional elementary row operations until you obtain a matrix in reduced row-echelon form.
where a is
A real number, then the solution set has the form
=infinite number of solutions
Solve the system