Q. Find all solutions by using the Gaussian elimination & Gauss-Jordan method: {x1+x2+2x3=−1x1−2x2+x3=−53x1+x2+x3=3
Write Augmented Matrix: Write the augmented matrix for the system of equations.⎣⎡1131−21211∣∣∣−1−53⎦⎤
Leading 1 in First Row: Perform row operations to get a leading 1 in the first row, first column (R1 is already set).No changes needed for R1.
Make Elements Zero: Make the elements below the leading 1 in the first column zero, using R2 - R1 → R2 and 3R1 - R3 → R3.⎣⎡1001−3−22−1−5∣∣∣−1−46⎦⎤
Leading 1 in Second Row: Get a leading 1 in the second row, second column by dividing R2 by −3.⎣⎡10011−221/3−5∣∣∣−14/36⎦⎤
Make Elements Zero: Make the elements above and below the leading 1 in the second column zero, using R1 - R2 → R1 and R3 + 2R2 → R3.⎣⎡1000105/31/3−13/3∣∣∣−7/34/314/3⎦⎤
Leading 1 in Third Row: Get a leading 1 in the third row, third column by dividing R3 by −13/3.⎣⎡1000105/31/31∣∣∣−7/34/3−14/13⎦⎤
Make Elements Zero: Make the elements above the leading 1 in the third column zero, using R1 - 5/3R3 → R1 and R2 - 1/3R3 → R2.⎣⎡100010001∣∣∣12−14/13⎦⎤