Homework Sourseplease help me Find matrix A whose first column is a1 1 2 1
please help me
Find matrix A whose first column is a_1 = [-1 2 1], third column is a_3 = [2 -1 -2], and reduced row echelon form is R = [1 3 0 1 3 0 0 1 3 2 0 0 0 0 0].Solution
It is apparent from the RREF of A that the 2nd column of A is a2 = 3a1 = 3(-1,2,1)T = (-3,6, 3)T , its 4th column is a4 = a1 +3a3 = (-1,2,1)T + 3 (2,-1,-2)T = (-1,2,1)T + (6,-3,-6)T = (5,-1,-5)T and its 5th column is a5 = 3a1+2a3 = 3(-1,2,1)T +2(2,-1,-2)T = (-3,6,3)T +(4,-2,-4)T = (1,4,-1)T. Therefore, A =
| -1 | -3 | 2 | -1 | 1 |
| 2 | 6 | -1 | 2 | 4 |
| 1 | 3 | -2 | 1 | -1 |
![please help me Find matrix A whose first column is a_1 = [-1 2 1], third column is a_3 = [2 -1 -2], and reduced row echelon form is R = [1 3 0 1 3 0 0 1 3 2 0 0](/WebImages/32/please-help-me-find-matrix-a-whose-first-column-is-a1-1-2-1-1093861-1761576407-0.webp "please help me Find matrix A whose first column is a_1 = [-1 2 1], third column is a_3 = [2 -1 -2], and reduced row echelon form is R = [1 3 0 1 3 0 0 1 3 2 0 0")
