180 likes | 441 Views
10.3 Systems of Linear Equations: Matrices. A matrix is defined as a rectangular array of numbers,. Column j. Column n. Column 1. Column 2. Row 1. Row 2. Row 3. Row 4. Augmented Matrix:. Row Operations on an Augmented Matrix. 1. Interchange any two rows.
E N D
A matrix is defined as a rectangular array of numbers, Column j Column n Column 1 Column 2 Row 1 Row 2 Row 3 Row 4
Row Operations on an Augmented Matrix 1. Interchange any two rows. 2. Replace a row by a nonzero multiple of that row. 3. Replace a row by the sum of that row and a constant multiple of some other row.
Solve Find the augmented matrix: Find the echelon form. R2=-2 R1+R2
R2 =R2/3 R3 =-4R2+R3
R3=R3*(-3/25) The third row of the matrix represents the equation z =-7/25. Substituting this into the equation represented by the second row we get:
Let z =-7/25, y =-44/25 in the first: Solution is:
Solve using a graphing utility.
Substitute z = 5 into the second. Substitute z=5, y =-2 into the first.
Solve using a graphing utility: Using rref(.) function we get: Dependent system: Infinitely many solutions.
Solve for y from the second: Solve for x from the first: Solution is (x, y, z) = (18/5 - (7/5)z, 7/5 + (2/5)z, z)